Past Simple

For finished actions or situations at specific times in the past.

Example: "I visited London last year."

Past Continuous

For activities in progress at a moment in the past.

Example: "I was watching TV at 8 PM yesterday."

Present Perfect

For actions that happened in the past at an unspecified moment, and you can see the result in the present.

Example: "I have lost my keys."

Past Perfect

For completed actions that happened in the past before another moment or action in the past.

Example: "I had finished my homework before dinner."

Present Perfect Continuous

For actions that started in the past and are either incomplete or finished very recently, especially when the duration is more important.

Example: "I have been working here for five years."

Past Perfect Continuous

To talk about actions that happened before another action in the past when the duration of the action is more important.

Example: "I had been waiting for an hour when she arrived."

Future in the Past (often using "would" or "was/were going to")

To talk about the past, when you want to talk about something that was in the future at that time, something which had not happened and perhaps didn't actually happen in the end.

Example: "I was going to call you, but I forgot." Or: "She said she would come."