• Android
• iOS
• Desktop

Android

To change the language:

1. Open Signal.
2. Tap your profile to go to Signal Settings.
3. Select Appearance.
4. Select the last item Language. 
5. Scroll through and select the language for it to apply immediately.

iOS

To change the language:

1. Follow steps from Apple's support page to ensure the language is enabled in iOS Settings.
2. Go to iOS Settings > Signal.
3. Select Language.
4. Scroll through and select the language for it to apply immediately

Desktop

To change the language:

1. Open Signal.
2. Select  Preferences.
3. Select Appearance.
4. Select Language.
5. Scroll through and select the language.
6. Select Set for it to apply immediately.

To manage spell check:

1. In Signal, open  Preferences.
2. Under Chats, select or deselect Enable spell check of text entered in message composition box.