Cách sử dụng
The expression "teach your grandmother to suck eggs" means to give advice or instructions to someone who is already familiar with or experienced in the topic, often in a patronizing or insulting way. It is usually used in a joking or lighthearted manner, and not meant to be taken literally. For example, if someone is explaining how to use a computer to an elderly person who is already proficient in using technology, someone may say "Oh don't bother, you don't need to teach your grandmother to suck eggs!"