‘A piece of cake’– something is very easy.
‘You can’t judge a book by its cover’ means to not judge someone or something based solely on appearance.
‘Let the cat out of the bag’ means to accidentally reveal a secret.
‘Once in a blue moon’ is a situation or event that happens infrequently.
‘Break a leg’ means ‘good luck’ (often said to actors before they go on stage).
‘To hit the nail on the head’ means to describe exactly what is causing a situation or problem.
‘The best of both worlds’ means you can enjoy two different opportunities at the same time.
If you see a friend in a photo, you could say: ‘I know her!’ However, next to your friend in the picture is another man.
‘Speak of the devil’ means that the person you’re just talking about actually appears at that moment.
To see eye to eye with someone means to agree with them; to think alike; to have similar opinions or viewpoints.