Use 'then' to show a time when something happened before or will happen. It helps tell when an event takes place.
We met then in 2010.
I will call you then tomorrow.
'Then' is used to show what happens next or as a result. It often connects actions in order.
First eat, then wash your hands.
Finish work, then you can rest.
Use 'then' to show what follows logically from a condition or idea. It means 'in that case' or 'so'.
If you are tired, then rest now.
If it rains, then stay inside.
'Then' as an adjective describes someone or something related to a specific past time. It shows who or what existed at that time.
The then president was very popular.
Her then husband lives abroad.
'Then' can be a noun meaning a specific time or moment. It is more formal or literary and less common in speaking.
The then of decision had arrived.
At the then, nothing was clear.
'Then' links a cause and its effect in logical or mathematical statements. It shows what happens after a condition.
If x > 0, then x has no negative value.
If true, then run the program.
'Then' is sometimes used like a small exclamation to push or encourage someone. It shows impatience or asking for action.
Then, tell me what you think!
Oh, then! Hurry up, please!