overstep the mark

black mark

Something that negatively affects someone's reputation.

easy mark

Someone who is easily fooled or victimized.

get off the mark

To score one's first points

make one's mark

To make, or leave, a lasting impression, especially to achieve prominent success.

mark my words

Listen to me; used before or after a statement one wishes to emphasize, especially a prediction.

mark one's own homework

To assume the role of evaluating one's doings when a disinterested party is required.

mark someone's card

To forcefully correct someone's behaviour.

quick off the mark

fast to act or react