Good morning, good afternoon, good evening

Good night is a goodbye, not a hello: Cambridge says it is used when people leave in the evening or go to bed.

English has greetings for different times of day. They are a little more polite than hi, so they are common at work, in shops, at school and with older people. Good morning is used from when you wake up until about noon. Good afternoon is used from noon until about five or six o’clock. Good evening is used after that, when it is getting dark or after work. These times are not strict rules, only common habits.

Good night is for leaving

Many learners say good night as a hello in the evening. In English that sounds strange. Cambridge Dictionary explains that good night is said when people leave each other in the evening or before going to bed or to sleep. So, when you arrive at a dinner at 8 pm, say good evening. When you leave at 11 pm, say good night. Parents say good night to children at bedtime, often with sleep well.

Short forms

In casual speech, people often drop good: Morning! Afternoon! Evening! Morning! is very common at work when colleagues arrive. Cambridge also lists night as an informal short form of good night, as in Night, Mum. These short forms are friendly but a little less polite, so use the full form with customers, teachers and people you do not know.

You can also put the time greeting together with other words. Good morning, everyone is a good way to start a class or a meeting. Good morning, Mrs Lee is polite with a teacher or neighbor. A shop assistant may say Good afternoon, how can I help you? You can reply Good afternoon, and then ask your question.

Some time phrases are only for goodbyes. Have a nice day, Have a good evening and Have a good weekend wish the other person a good time after you leave. On a Friday afternoon at work or school, you will hear Have a good weekend! many times. The usual answer is Thanks, you too! The same answer works for all of these wishes, so it is a very useful line to learn.