1. He LEFT school 2 years ago 2. I LIVED in Cardiff for 2 years, then I moved to Swansea. 3. Correct 4. My sister HAD her baby yesterday 5. Correct 6. Correct 7. Correct 8. I MET Sandra when I WAS at university You want to use the present perfect (have + verb) when the word that expresses the time INCLUDES NOW. For example today, this week, this year, since I was 12, for 15 years (including now). We use the simple past when the time expression does not include now. For example yesterday, last week, when I was 2, 7 years ago etc. An example of both would be: "I've eaten an apple today." - this includes now as we are using 'today'. "I ate an apple yesterday" - this does not include now as we are using 'yesterday'. I hope this explanation makes it clearer for you! :)

1. HE LEFT school two years ago. [statement of event in the past, now finished, so simple past] 2. I LIVED in Cardiff for two years, but then . . [as above] 3. √ [and she is still living there/[here if speaker is also in F.] 4. My sister HAD her baby yesterday ! [statement of event in the past, now finished] 5. √ [and I am still working there, so present perfect] 6. √ [and may still be changing, so present perfect] 7. They ARE divorced now. THEY WERE married for ten years. 8. I MET Sandra when I WAS at university. [past event, now finished, so simple past]

Thanks a lot!!!

1. HE LEFT school two years ago. (Past event which has been completed) 2. I LIVED in Cardiff for two years, but then I moved to Swansea. (Past event which has been completed) 3. SHE'S LIVED in Florida since 2010. - CORRECT - Event which began in the past and continues without any change. If you said SHE LIVED it would mean that she lived there in the past, but doesn't any longer. 4. My sister HAD her baby yesterday! - Past event which has been completed 5. I'VE WORKED there for 20 years. - This is correct if you are saying that you STILL work there now. 6. The city HAS CHANGED a lot since I was a child. - CORRECT 7. They are divorced now. THEY WERE married for ten years. - CORRECT 8. I'VE MET Sandra when I've been at university. - I MET Sandra when I WAS at university. - (I met - Past event which has been completed, I was - Past event which has been completed).