Most common idioms in English
1. A penny for your thoughts - this idiom is used as a way to ask someone what they are thinking about
2. Once in a blue moon - this is used when something happens very rarely
3. On the ball - when someone understands the situation well
4.Cut corners - when someone buys products that are cheap but not of good quality.
5. See eye to eye - This idiom is used to say that two (or more people) agree on something.
6. Courisity killed the cat (you have a picture) - This idiom is used when someone is too curious