diff --git a/Packages/MoraCore/Sources/MoraCore/EnglishL1Profile.swift b/Packages/MoraCore/Sources/MoraCore/EnglishL1Profile.swift
index 2fcc16ad..1952dc1e 100644
--- a/Packages/MoraCore/Sources/MoraCore/EnglishL1Profile.swift
+++ b/Packages/MoraCore/Sources/MoraCore/EnglishL1Profile.swift
@@ -162,7 +162,10 @@ public struct EnglishL1Profile: L1Profile {
         completionComeBack: "See you tomorrow!",
         a11yCloseSession: "End the quest",
         a11yMicButton: "Mic",
-        a11yStreakChip: { days in "\(days)-day streak" }
-        // PR 3 will append the four language-switch fields.
+        a11yStreakChip: { days in "\(days)-day streak" },
+        homeChangeLanguageButton: "Change language",
+        languageSwitchSheetTitle: "Pick a language",
+        languageSwitchSheetCancel: "Cancel",
+        languageSwitchSheetConfirm: "Done"
     )
 }
diff --git a/Packages/MoraCore/Sources/MoraCore/JapaneseL1Profile.swift b/Packages/MoraCore/Sources/MoraCore/JapaneseL1Profile.swift
index 47f4f693..66380c28 100644
--- a/Packages/MoraCore/Sources/MoraCore/JapaneseL1Profile.swift
+++ b/Packages/MoraCore/Sources/MoraCore/JapaneseL1Profile.swift
@@ -297,7 +297,11 @@ public struct JapaneseL1Profile: L1Profile {
         a11yCloseSession: "クエストを おわる",
         a11yMicButton: "マイク",
         // `日` G1 kept.
-        a11yStreakChip: { days in "\(days)日 れんぞく" }
+        a11yStreakChip: { days in "\(days)日 れんぞく" },
+        homeChangeLanguageButton: "ことばを かえる",
+        languageSwitchSheetTitle: "ことばを えらぶ",
+        languageSwitchSheetCancel: "キャンセル",
+        languageSwitchSheetConfirm: "OK"
     )
 
     /// Ages ≤6 (entry tier). Kanji budget: empty — every kanji collapses to
@@ -434,7 +438,11 @@ public struct JapaneseL1Profile: L1Profile {
         a11yCloseSession: "クエストを おわる",
         a11yMicButton: "マイク",
         // `日` G1 → にち
-        a11yStreakChip: { days in "\(days)にち れんぞく" }
+        a11yStreakChip: { days in "\(days)にち れんぞく" },
+        homeChangeLanguageButton: "ことばを かえる",
+        languageSwitchSheetTitle: "ことばを えらぶ",
+        languageSwitchSheetCancel: "キャンセル",
+        languageSwitchSheetConfirm: "OK"
     )
 
     /// Ages 8+ (advanced tier). Kanji budget: only JPKanjiLevel.grade1And2
@@ -554,6 +562,10 @@ public struct JapaneseL1Profile: L1Profile {
         completionComeBack: "明日も またね",
         a11yCloseSession: "クエストを おわる",
         a11yMicButton: "マイク",
-        a11yStreakChip: { days in "\(days)日 れんぞく" }
+        a11yStreakChip: { days in "\(days)日 れんぞく" },
+        homeChangeLanguageButton: "ことばを かえる",
+        languageSwitchSheetTitle: "ことばを えらぶ",
+        languageSwitchSheetCancel: "キャンセル",
+        languageSwitchSheetConfirm: "OK"
     )
 }
diff --git a/Packages/MoraCore/Sources/MoraCore/KoreanL1Profile.swift b/Packages/MoraCore/Sources/MoraCore/KoreanL1Profile.swift
index f0fa1a97..24737e2c 100644
--- a/Packages/MoraCore/Sources/MoraCore/KoreanL1Profile.swift
+++ b/Packages/MoraCore/Sources/MoraCore/KoreanL1Profile.swift
@@ -203,6 +203,10 @@ public struct KoreanL1Profile: L1Profile {
         completionComeBack: "내일 또 만나요",
         a11yCloseSession: "퀘스트를 끝내기",
         a11yMicButton: "마이크",
-        a11yStreakChip: { days in "\(days)일 연속" }
+        a11yStreakChip: { days in "\(days)일 연속" },
+        homeChangeLanguageButton: "언어 바꾸기",
+        languageSwitchSheetTitle: "언어 선택",
+        languageSwitchSheetCancel: "취소",
+        languageSwitchSheetConfirm: "확인"
     )
 }
diff --git a/Packages/MoraCore/Sources/MoraCore/MoraStrings.swift b/Packages/MoraCore/Sources/MoraCore/MoraStrings.swift
index feab455a..abe10b66 100644
--- a/Packages/MoraCore/Sources/MoraCore/MoraStrings.swift
+++ b/Packages/MoraCore/Sources/MoraCore/MoraStrings.swift
@@ -128,6 +128,12 @@ public struct MoraStrings: Sendable {
     public let a11yMicButton: String
     public let a11yStreakChip: @Sendable (Int) -> String
 
+    // In-app language switch (Home globe button + sheet)
+    public let homeChangeLanguageButton: String
+    public let languageSwitchSheetTitle: String
+    public let languageSwitchSheetCancel: String
+    public let languageSwitchSheetConfirm: String
+
     public init(
         ageOnboardingPrompt: String,
         ageOnboardingCTA: String,
@@ -199,7 +205,11 @@ public struct MoraStrings: Sendable {
         completionScore: @escaping @Sendable (Int, Int) -> String,
         completionComeBack: String,
         a11yCloseSession: String, a11yMicButton: String,
-        a11yStreakChip: @escaping @Sendable (Int) -> String
+        a11yStreakChip: @escaping @Sendable (Int) -> String,
+        homeChangeLanguageButton: String,
+        languageSwitchSheetTitle: String,
+        languageSwitchSheetCancel: String,
+        languageSwitchSheetConfirm: String
     ) {
         self.ageOnboardingPrompt = ageOnboardingPrompt
         self.ageOnboardingCTA = ageOnboardingCTA
@@ -290,6 +300,10 @@ public struct MoraStrings: Sendable {
         self.a11yCloseSession = a11yCloseSession
         self.a11yMicButton = a11yMicButton
         self.a11yStreakChip = a11yStreakChip
+        self.homeChangeLanguageButton = homeChangeLanguageButton
+        self.languageSwitchSheetTitle = languageSwitchSheetTitle
+        self.languageSwitchSheetCancel = languageSwitchSheetCancel
+        self.languageSwitchSheetConfirm = languageSwitchSheetConfirm
     }
 }
 
diff --git a/Packages/MoraCore/Tests/MoraCoreTests/LocaleScriptBudgetTests.swift b/Packages/MoraCore/Tests/MoraCoreTests/LocaleScriptBudgetTests.swift
index 7794846c..203d6f53 100644
--- a/Packages/MoraCore/Tests/MoraCoreTests/LocaleScriptBudgetTests.swift
+++ b/Packages/MoraCore/Tests/MoraCoreTests/LocaleScriptBudgetTests.swift
@@ -147,5 +147,9 @@ func everyStringField(_ s: MoraStrings) -> [(name: String, value: String)] {
         ("a11yCloseSession", s.a11yCloseSession),
         ("a11yMicButton", s.a11yMicButton),
         ("a11yStreakChip(5)", s.a11yStreakChip(5)),
+        ("homeChangeLanguageButton", s.homeChangeLanguageButton),
+        ("languageSwitchSheetTitle", s.languageSwitchSheetTitle),
+        ("languageSwitchSheetCancel", s.languageSwitchSheetCancel),
+        ("languageSwitchSheetConfirm", s.languageSwitchSheetConfirm),
     ]
 }
diff --git a/Packages/MoraUI/Sources/MoraUI/Home/HomeView.swift b/Packages/MoraUI/Sources/MoraUI/Home/HomeView.swift
index 5eccd7c8..1bdd8a44 100644
--- a/Packages/MoraUI/Sources/MoraUI/Home/HomeView.swift
+++ b/Packages/MoraUI/Sources/MoraUI/Home/HomeView.swift
@@ -8,6 +8,8 @@ import SwiftUI
 import UIKit
 #endif
 
+private let homeViewLog = Logger(subsystem: "tech.reenable.Mora", category: "HomeView")
+
 #if DEBUG
 private let debugBarLog = Logger(subsystem: "tech.reenable.Mora", category: "DebugBar")
 #endif
@@ -60,11 +62,10 @@ public struct HomeView: View {
     // after downloading a premium voice flips the gate off immediately.
     @State private var needsBetterVoice: Bool = AppleTTSEngine.needsEnhancedVoice
     @State private var installedVoices: [String] = AppleTTSEngine.installedEnglishVoiceSummaries()
+    @State private var languageSheet: LanguageSwitchSheet?
     @Environment(\.scenePhase) private var scenePhase
     @Environment(\.moraStrings) private var strings
-    #if DEBUG
-    @Environment(\.modelContext) private var debugContext
-    #endif
+    @Environment(\.modelContext) private var modelContext
 
     public init() {}
 
@@ -98,6 +99,10 @@ public struct HomeView: View {
             YokaiIntroFlow(mode: .replay) { showYokaiIntroReplay = false }
                 .environment(\.moraStrings, strings)
         }
+        .sheet(item: $languageSheet) { model in
+            LanguageSwitchSheetView(model: model)
+                .environment(\.moraStrings, strings)
+        }
         #if os(iOS)
         .navigationBarHidden(true)
         #endif
@@ -106,6 +111,38 @@ public struct HomeView: View {
     private var header: some View {
         HStack {
             wordmark
+            Button {
+                guard let profile = profiles.first else { return }
+                let previousID = profile.l1Identifier
+                languageSheet = LanguageSwitchSheet(
+                    currentIdentifier: previousID,
+                    onCommit: { newID in
+                        profile.l1Identifier = newID
+                        do {
+                            try modelContext.save()
+                            languageSheet = nil
+                        } catch {
+                            // Revert the in-memory change so it doesn't drift
+                            // from disk; leave the sheet open so the user sees
+                            // their tap didn't take rather than silently losing
+                            // it on next launch.
+                            profile.l1Identifier = previousID
+                            homeViewLog.error(
+                                "Failed to persist language switch to \(newID, privacy: .public): \(error.localizedDescription, privacy: .public)"
+                            )
+                        }
+                    },
+                    onCancel: {
+                        languageSheet = nil
+                    }
+                )
+            } label: {
+                Image(systemName: "globe")
+                    .foregroundStyle(MoraTheme.Ink.muted)
+            }
+            .buttonStyle(.plain)
+            .accessibilityLabel(strings.homeChangeLanguageButton)
+
             Spacer()
             StreakChip(count: streaks.first?.currentCount ?? 0)
         }
@@ -390,7 +427,7 @@ public struct HomeView: View {
             streak = existing
         } else {
             streak = DailyStreak()
-            debugContext.insert(streak)
+            modelContext.insert(streak)
         }
         // Route through the real DailyStreak rules instead of mutating fields
         // directly: simulate "the next day" so each tap counts as one more
@@ -430,7 +467,7 @@ public struct HomeView: View {
 
         var befriendedIDs = Set(bestiary.map(\.yokaiID))
         if let id = currentYokaiID, !befriendedIDs.contains(id) {
-            debugContext.insert(BestiaryEntryEntity(yokaiID: id, befriendedAt: now))
+            modelContext.insert(BestiaryEntryEntity(yokaiID: id, befriendedAt: now))
             befriendedIDs.insert(id)
         }
 
@@ -438,7 +475,7 @@ public struct HomeView: View {
             !befriendedIDs.contains($0)
         })
         if let nextID {
-            debugContext.insert(
+            modelContext.insert(
                 YokaiEncounterEntity(
                     yokaiID: nextID,
                     weekStart: now,
@@ -460,9 +497,9 @@ public struct HomeView: View {
     private func resetCurriculum() {
         debugBarLog.info("resetCurriculum: wiping encounters, bestiary, cameos, streak, profile.createdAt")
         do {
-            try debugContext.delete(model: YokaiEncounterEntity.self)
-            try debugContext.delete(model: BestiaryEntryEntity.self)
-            try debugContext.delete(model: YokaiCameoEntity.self)
+            try modelContext.delete(model: YokaiEncounterEntity.self)
+            try modelContext.delete(model: BestiaryEntryEntity.self)
+            try modelContext.delete(model: YokaiCameoEntity.self)
         } catch {
             assertionFailure("Failed to delete debug models: \(error)")
         }
@@ -479,7 +516,7 @@ public struct HomeView: View {
 
     private func persistDebugChanges() {
         do {
-            try debugContext.save()
+            try modelContext.save()
         } catch {
             assertionFailure("Failed to persist debug change: \(error)")
         }
diff --git a/Packages/MoraUI/Sources/MoraUI/LanguageAge/AgePickerView.swift b/Packages/MoraUI/Sources/MoraUI/LanguageAge/AgePickerView.swift
index 17eadfb8..21fecab6 100644
--- a/Packages/MoraUI/Sources/MoraUI/LanguageAge/AgePickerView.swift
+++ b/Packages/MoraUI/Sources/MoraUI/LanguageAge/AgePickerView.swift
@@ -7,15 +7,6 @@ struct AgePickerView: View {
     @Binding var selectedAge: Int?
     let onContinue: () -> Void
 
-    /// 4..12 plus a sentinel `13` that renders as "13+" and maps to the
-    /// 13-and-over bucket internally. Under-4 is out of scope in alpha.
-    private let ages: [Int] = Array(4...12) + [13]
-    private let columns = [
-        GridItem(.flexible(), spacing: MoraTheme.Space.md),
-        GridItem(.flexible(), spacing: MoraTheme.Space.md),
-        GridItem(.flexible(), spacing: MoraTheme.Space.md),
-    ]
-
     var body: some View {
         ZStack {
             MoraTheme.Background.page.ignoresSafeArea()
@@ -25,8 +16,8 @@ struct AgePickerView: View {
                     .foregroundStyle(MoraTheme.Ink.primary)
                     .padding(.top, MoraTheme.Space.xxl)
 
-                LazyVGrid(columns: columns, spacing: MoraTheme.Space.md) {
-                    ForEach(ages, id: \.self) { age in
+                HStack(spacing: MoraTheme.Space.md) {
+                    ForEach(LanguageAgeFlow.ageOptions, id: \.self) { age in
                         tile(age)
                     }
                 }
@@ -62,12 +53,11 @@ struct AgePickerView: View {
 
     private func tile(_ age: Int) -> some View {
         let selected = selectedAge == age
-        let label = age == 13 ? "13+" : "\(age)"
         return Button {
             selectedAge = age
         } label: {
-            Text(label)
-                .font(MoraType.hero(72))
+            Text("\(age)")
+                .font(MoraType.hero(120))
                 .foregroundStyle(MoraTheme.Ink.primary)
                 .frame(maxWidth: .infinity, minHeight: 120)
                 .background(
diff --git a/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguageAgeFlow.swift b/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguageAgeFlow.swift
index d5c528bd..91ca4106 100644
--- a/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguageAgeFlow.swift
+++ b/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguageAgeFlow.swift
@@ -9,7 +9,7 @@ import SwiftUI
 final class LanguageAgeState {
     var step: Step = .language
     var selectedLanguageID: String
-    var selectedAge: Int? = 8  // pre-selected per spec §6.2
+    var selectedAge: Int? = LanguageAgeFlow.defaultAge  // pre-selected per spec §7.2
 
     static let onboardedKey = "tech.reenable.Mora.languageAgeOnboarded"
 
@@ -99,6 +99,13 @@ public struct LanguageAgeFlow: View {
         self.onFinished = onFinished
     }
 
+    /// Age tiles shown in Step 2. Narrowed in PR 3 to the dyslexia
+    /// intervention window (6–8 = JP 小学校低学年). See spec §7.2.
+    public static let ageOptions: [Int] = [6, 7, 8]
+
+    /// Default selected age in Step 2 — middle of the target range.
+    public static let defaultAge: Int = 7
+
     /// Identifiers of language rows that are tap-enabled. See spec §7.4.
     public static let activeLanguageIdentifiers: [String] = ["ja", "ko", "en"]
 
diff --git a/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguagePicker.swift b/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguagePicker.swift
new file mode 100644
index 00000000..6ca11c0b
--- /dev/null
+++ b/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguagePicker.swift
@@ -0,0 +1,99 @@
+// Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguagePicker.swift
+import MoraCore
+import SwiftUI
+
+/// Reusable language-selection row list.
+///
+/// Renders the locale-neutral header and one tappable row per language.
+/// Active vs. coming-soon status is driven by `LanguageAgeFlow` so the
+/// activation list stays in one place.
+public struct LanguagePicker: View {
+    @Binding public var selection: String
+
+    public init(selection: Binding<String>) {
+        _selection = selection
+    }
+
+    private struct Option: Identifiable {
+        let id: String
+        let label: String
+        let enabled: Bool
+    }
+
+    private static let allOptions: [(id: String, label: String)] = [
+        (id: "ja", label: "にほんご"),
+        (id: "ko", label: "한국어"),
+        (id: "zh", label: "中文"),
+        (id: "en", label: "English"),
+    ]
+
+    private var options: [Option] {
+        let active = Set(LanguageAgeFlow.activeLanguageIdentifiers)
+        return Self.allOptions.map { entry in
+            Option(id: entry.id, label: entry.label, enabled: active.contains(entry.id))
+        }
+    }
+
+    public var body: some View {
+        VStack(spacing: MoraTheme.Space.xl) {
+            Text("Language / 言語 / 语言 / 언어")
+                .font(MoraType.label())
+                .foregroundStyle(MoraTheme.Ink.muted)
+                .padding(.top, MoraTheme.Space.xxl)
+
+            VStack(spacing: MoraTheme.Space.sm) {
+                ForEach(options) { option in
+                    row(option)
+                }
+            }
+            .padding(.horizontal, MoraTheme.Space.xxl)
+        }
+    }
+
+    private func row(_ option: Option) -> some View {
+        let selected = option.id == selection
+        return Button {
+            guard option.enabled else { return }
+            selection = option.id
+        } label: {
+            HStack {
+                Text(option.label)
+                    .font(MoraType.heading())
+                    .foregroundStyle(
+                        option.enabled
+                            ? MoraTheme.Ink.primary
+                            : MoraTheme.Ink.muted
+                    )
+                if !option.enabled {
+                    Spacer()
+                    Text("Coming soon")
+                        .font(MoraType.pill())
+                        .foregroundStyle(MoraTheme.Ink.muted)
+                } else if selected {
+                    Spacer()
+                    Image(systemName: "checkmark")
+                        .foregroundStyle(MoraTheme.Accent.orange)
+                } else {
+                    Spacer()
+                }
+            }
+            .padding(MoraTheme.Space.md)
+            .background(
+                selected
+                    ? MoraTheme.Background.peach
+                    : MoraTheme.Background.cream,
+                in: RoundedRectangle(cornerRadius: MoraTheme.Radius.tile)
+            )
+            .overlay(
+                RoundedRectangle(cornerRadius: MoraTheme.Radius.tile)
+                    .stroke(
+                        selected ? MoraTheme.Accent.orange : .clear,
+                        lineWidth: 3
+                    )
+            )
+        }
+        .buttonStyle(.plain)
+        .disabled(!option.enabled)
+        .accessibilityAddTraits(selected ? .isSelected : [])
+    }
+}
diff --git a/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguagePickerView.swift b/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguagePickerView.swift
index a916a820..edaed7e4 100644
--- a/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguagePickerView.swift
+++ b/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguagePickerView.swift
@@ -6,41 +6,11 @@ struct LanguagePickerView: View {
     @Binding var selectedLanguageID: String
     let onContinue: () -> Void
 
-    private struct Option: Identifiable {
-        let id: String
-        let label: String
-        let enabled: Bool
-    }
-
-    private static let allOptions: [(id: String, label: String)] = [
-        (id: "ja", label: "にほんご"),
-        (id: "ko", label: "한국어"),
-        (id: "zh", label: "中文"),
-        (id: "en", label: "English"),
-    ]
-
-    private var options: [Option] {
-        let active = Set(LanguageAgeFlow.activeLanguageIdentifiers)
-        return Self.allOptions.map { entry in
-            Option(id: entry.id, label: entry.label, enabled: active.contains(entry.id))
-        }
-    }
-
     var body: some View {
         ZStack {
             MoraTheme.Background.page.ignoresSafeArea()
             VStack(spacing: MoraTheme.Space.xl) {
-                Text("Language / 言語 / 语言 / 언어")
-                    .font(MoraType.label())
-                    .foregroundStyle(MoraTheme.Ink.muted)
-                    .padding(.top, MoraTheme.Space.xxl)
-
-                VStack(spacing: MoraTheme.Space.sm) {
-                    ForEach(options) { option in
-                        row(option)
-                    }
-                }
-                .padding(.horizontal, MoraTheme.Space.xxl)
+                LanguagePicker(selection: $selectedLanguageID)
 
                 Spacer()
 
@@ -71,51 +41,4 @@ struct LanguagePickerView: View {
             }
         }
     }
-
-    private func row(_ option: Option) -> some View {
-        let selected = option.id == selectedLanguageID
-        return Button {
-            guard option.enabled else { return }
-            selectedLanguageID = option.id
-        } label: {
-            HStack {
-                Text(option.label)
-                    .font(MoraType.heading())
-                    .foregroundStyle(
-                        option.enabled
-                            ? MoraTheme.Ink.primary
-                            : MoraTheme.Ink.muted
-                    )
-                if !option.enabled {
-                    Spacer()
-                    Text("Coming soon")
-                        .font(MoraType.pill())
-                        .foregroundStyle(MoraTheme.Ink.muted)
-                } else if selected {
-                    Spacer()
-                    Image(systemName: "checkmark")
-                        .foregroundStyle(MoraTheme.Accent.orange)
-                } else {
-                    Spacer()
-                }
-            }
-            .padding(MoraTheme.Space.md)
-            .background(
-                selected
-                    ? MoraTheme.Background.peach
-                    : MoraTheme.Background.cream,
-                in: RoundedRectangle(cornerRadius: MoraTheme.Radius.tile)
-            )
-            .overlay(
-                RoundedRectangle(cornerRadius: MoraTheme.Radius.tile)
-                    .stroke(
-                        selected ? MoraTheme.Accent.orange : .clear,
-                        lineWidth: 3
-                    )
-            )
-        }
-        .buttonStyle(.plain)
-        .disabled(!option.enabled)
-        .accessibilityAddTraits(selected ? .isSelected : [])
-    }
 }
diff --git a/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguageSwitchSheet.swift b/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguageSwitchSheet.swift
new file mode 100644
index 00000000..7e922ea8
--- /dev/null
+++ b/Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguageSwitchSheet.swift
@@ -0,0 +1,81 @@
+// Packages/MoraUI/Sources/MoraUI/LanguageAge/LanguageSwitchSheet.swift
+import MoraCore
+import SwiftUI
+
+/// Sheet that lets the user re-pick the L1 from Home, without re-running
+/// onboarding. Reuses `LanguagePicker`. Writes only `LearnerProfile.l1Identifier`;
+/// age / level / interests / font are not touched. See spec §7.3.
+@MainActor
+public final class LanguageSwitchSheet: ObservableObject {
+    public let currentIdentifier: String
+    private let onCommit: (String) -> Void
+    private let onCancel: () -> Void
+
+    @Published public var pickedID: String
+
+    public init(
+        currentIdentifier: String,
+        onCommit: @escaping (String) -> Void,
+        onCancel: @escaping () -> Void
+    ) {
+        self.currentIdentifier = currentIdentifier
+        self.onCommit = onCommit
+        self.onCancel = onCancel
+        self.pickedID = currentIdentifier
+    }
+
+    public var isConfirmDisabled: Bool {
+        pickedID == currentIdentifier
+    }
+
+    public func select(identifier: String) {
+        pickedID = identifier
+    }
+
+    public func confirm() {
+        guard !isConfirmDisabled else { return }
+        onCommit(pickedID)
+    }
+
+    public func cancel() {
+        onCancel()
+    }
+}
+
+extension LanguageSwitchSheet: Identifiable {
+    public var id: String { currentIdentifier }
+}
+
+/// SwiftUI rendering of the sheet model. Hosted as a `.sheet` from `HomeView`.
+public struct LanguageSwitchSheetView: View {
+    @ObservedObject var model: LanguageSwitchSheet
+    @Environment(\.moraStrings) private var strings
+
+    public init(model: LanguageSwitchSheet) {
+        self.model = model
+    }
+
+    public var body: some View {
+        NavigationStack {
+            LanguagePicker(selection: $model.pickedID)
+                .padding()
+                .navigationTitle(strings.languageSwitchSheetTitle)
+                #if os(iOS)
+            .navigationBarTitleDisplayMode(.inline)
+                #endif
+                .toolbar {
+                    ToolbarItem(placement: .cancellationAction) {
+                        Button(strings.languageSwitchSheetCancel) {
+                            model.cancel()
+                        }
+                    }
+                    ToolbarItem(placement: .confirmationAction) {
+                        Button(strings.languageSwitchSheetConfirm) {
+                            model.confirm()
+                        }
+                        .disabled(model.isConfirmDisabled)
+                    }
+                }
+        }
+    }
+}
diff --git a/Packages/MoraUI/Tests/MoraUITests/HomeViewLanguageSwitchTests.swift b/Packages/MoraUI/Tests/MoraUITests/HomeViewLanguageSwitchTests.swift
new file mode 100644
index 00000000..ec361de5
--- /dev/null
+++ b/Packages/MoraUI/Tests/MoraUITests/HomeViewLanguageSwitchTests.swift
@@ -0,0 +1,14 @@
+import XCTest
+import MoraCore
+@testable import MoraUI
+
+@MainActor
+final class HomeViewLanguageSwitchTests: XCTestCase {
+    func test_globe_a11yLabel_matchesMoraStrings() {
+        let strings = JapaneseL1Profile().uiStrings(at: .advanced)
+        XCTAssertEqual(strings.homeChangeLanguageButton, "ことばを かえる")
+    }
+
+    // Full SwiftUI render harness for sheet presentation is out of scope;
+    // the sheet's behavior is covered by LanguageSwitchSheetTests.
+}
diff --git a/Packages/MoraUI/Tests/MoraUITests/LanguageAgeFlowTests.swift b/Packages/MoraUI/Tests/MoraUITests/LanguageAgeFlowTests.swift
index e3d1b670..d080eb2e 100644
--- a/Packages/MoraUI/Tests/MoraUITests/LanguageAgeFlowTests.swift
+++ b/Packages/MoraUI/Tests/MoraUITests/LanguageAgeFlowTests.swift
@@ -130,4 +130,12 @@ final class LanguageAgeFlowTests: XCTestCase {
         )
         XCTAssertTrue(profiles.isEmpty)
     }
+
+    func test_agePicker_showsThreeTiles_for6_7_8() {
+        XCTAssertEqual(LanguageAgeFlow.ageOptions, [6, 7, 8])
+    }
+
+    func test_agePicker_defaultSelection_is7() {
+        XCTAssertEqual(LanguageAgeFlow.defaultAge, 7)
+    }
 }
diff --git a/Packages/MoraUI/Tests/MoraUITests/LanguageSwitchSheetTests.swift b/Packages/MoraUI/Tests/MoraUITests/LanguageSwitchSheetTests.swift
new file mode 100644
index 00000000..157eb129
--- /dev/null
+++ b/Packages/MoraUI/Tests/MoraUITests/LanguageSwitchSheetTests.swift
@@ -0,0 +1,50 @@
+import XCTest
+import MoraCore
+@testable import MoraUI
+
+@MainActor
+final class LanguageSwitchSheetTests: XCTestCase {
+    func test_onCommit_calledWithPickedID_whenConfirmTapped() {
+        var committed: String?
+        let sheet = LanguageSwitchSheet(
+            currentIdentifier: "ja",
+            onCommit: { committed = $0 },
+            onCancel: {}
+        )
+        sheet.select(identifier: "ko")
+        sheet.confirm()
+        XCTAssertEqual(committed, "ko")
+    }
+
+    func test_onCancel_called_whenCancelTapped() {
+        var cancelled = false
+        let sheet = LanguageSwitchSheet(
+            currentIdentifier: "ja",
+            onCommit: { _ in },
+            onCancel: { cancelled = true }
+        )
+        sheet.cancel()
+        XCTAssertTrue(cancelled)
+    }
+
+    func test_confirmDisabled_whenSelectionEqualsCurrent() {
+        let sheet = LanguageSwitchSheet(
+            currentIdentifier: "ja",
+            onCommit: { _ in XCTFail("should not commit") },
+            onCancel: {}
+        )
+        XCTAssertEqual(sheet.pickedID, "ja")
+        XCTAssertTrue(sheet.isConfirmDisabled)
+    }
+
+    func test_confirmEnabled_whenSelectionDiffersFromCurrent() {
+        let sheet = LanguageSwitchSheet(
+            currentIdentifier: "ja",
+            onCommit: { _ in },
+            onCancel: {}
+        )
+        sheet.select(identifier: "en")
+        XCTAssertEqual(sheet.pickedID, "en")
+        XCTAssertFalse(sheet.isConfirmDisabled)
+    }
+}