Explicit Language on Siri for iPhone is enabled by default. It means no bad language is blocked, some dirty words may be suggested when using Siri dictation and some mature language may be used when having a conversation with Siri. To turn off and disable explicit language on Siri for iPhone, do as follows:
1. Open the Settings application on your iPhone
2. Go to the General settings
3. Scroll down to the Restrictions menu and open it
4. Make sure the Restrictions mode is enabled (You may either have to enter your current restrictions passcode or define a new one)
5. Scroll down to the list of Allowed Content and tap the Siri option
6. Make sure the Explicit Language button is toggled off, so Siri will behave nicely with no offensive word suggestion