speak one’s mind

(verb) to give one’s opinion in a strong way

Example Sentences:

A: What do you think of global warming?
B: Well, if you want me to speak my mind, I feel like people aren’t doing enough to stop it!

People don’t like Lisa very much because she is always speaking her mind, even if people aren’t asking for it.

William was fired because he spoke his mind to his boss.

From the Blogs:

Don’t be afraid to speak your mind

Media:

Similar idioms:

1. give someone a piece of your mind
2. have something on one’s mind
3. one-track mind
4. blow one’s mind