Have is strong if it stands alone without a main verb. It is weak in the question form. Have is often contracted ('Ve) in statements if it is followed by a main verb.
1 Have you just finished your work?
2 They haven't lived here for years.
3 She's worked in the bank for five years.
4 Would you like something to eat? — I have just had something to eat.
5 I've worked hard this week.
6 It has rained a lot this year.
7 We haven't seen her today.
8 They've seen that film six times.
9 It has happened several times already.
10 Have you got a spare pen? — I don't think I have.
11 We've eaten at that restaurant many times.
12 Has he just left?
13 Someone has eaten my soup!
14 She's studied Japanese, Russian and English.