speak with a forked tongue

bite one's tongue

To resist the urge to speak out, especially in order to avoid saying something inappropriate or likely to cause a dispute.

cat got someone's tongue

Why is someone not saying anything?

civil tongue

A polite manner of speaking.

find one's tongue

To speak after being unable to do so or after remaining silent; to find something to say.

forked tongue

The characteristic of deceptiveness; duplicity; untruthfulness.

hold one's tongue

To refrain from talking about something.

keep a civil tongue in one's head

To maintain a polite manner of speaking.

lay one's tongue to

To say; to name; to think of to say.