|I have played tennis yesterday.||I played tennis yesterday.||You did it. It ended. You need the simple past.|
|I can’t play now. I do my homework.||I can’t play now. I am doing my homework.||You are still doing it. It’s continuous.|
|I live in London since last year.||I have been living in London since last year.||You are still living in London. It’s continuous.|
|I will tell you as soon as I will know.||I will tell you as soon as I know.||Time clauses introduced by “after”, “as soon as”, “until”, “when” do not take the future tense.|
Why is it “I have been living in London since last year” and not “I live in London since last year”? Because with SINCE you have to use the Present Perfect: the action started in the past. In French you use the present in that case “J’habite à Londre depuis…” but not in English!