Present perfect

1. Grammar explanation

1.1. Unfinished time and states

1.1.1. They've been on holiday twice this year. We haven't had a lot of positive feedback so far. I'm sure I've seen that film before.

1.2. Finished time and states

1.2.1. We visited Russia for the first time in 1992. I went to three different primary schools. Before she retired, she worked in several different countries.

1.3. Past actions with a result in the present

1.3.1. He's broken his leg so he can't go on holiday. There's been an accident on the main road, so let's take a different route. They haven't called me, so I don't think they need me today.