There are many popular idioms in English, but some of the most common include:
1- A bird in the hand is worth two in the bush.** This means that it is better to have something that you know is good than to risk getting -something that might be better.
2- Don’t count your chickens before they hatch.** This means that you should not be too optimistic about something that has not yet happened.
3- The early bird gets the worm.** This means that it is better to be early than late, especially if you are trying to get something that is in high demand.
4- A friend in need is a friend indeed.** This means that a true friend is someone who is there for you when you need them most.
5- It takes two to tango.** This means that it takes two people to make a relationship work.
6- You can’t have your cake and eat it too.** This means that you cannot have two things that are mutually exclusive.
7- The grass is always greener on the other side of the fence.** This means that you are always more attracted to something that you do not have.
8- A leopard cannot change its spots.** This means that a person’s character cannot be changed.
9- You can lead a horse to water, but you cannot make it drink.** This means that you can provide someone with the opportunity to do something, but you cannot force them to do it.
These are just a few of the many popular idioms in English. If you are learning English, it is helpful to learn some of these idioms so that you can understand them when you hear them.