Answer:
1) I can't go with you.
Interrogative: Can't I go with you?
2) They can paint the house.
Interrogative: Can they paint the house?
3) I can help you.
Interrogative: Can I help you?
4) Can you come here?
Interrogative: Can you come here?
5) You can stop here.
Interrogative: Can you stop here?
6) Can you obtain a visitor's visa?
Interrogative: Can you obtain a visitor's visa?
7) I can't lift this weight.
Interrogative: Can I not lift this weight?
8) I can't come sooner.
Interrogative: Can't I come sooner?
9) She can't come this summer.
Interrogative: can't she come this summer?
10) He can finish the race.
Interrogative: Can he finish the race?
11) I can't answer the question.
Interrogative: Can't I help you?
12) we can score a goal.
Interrogative: Can we score a goal?
13) We can help you.
Interrogative: Can we help you?
14) Can you sing?
Interrogative: Can you sing?
15) They can't enter the party.
Interrogative: Can they not enter the party?
16) Can you enter?
Interrogative: Can you enter?
17) I can't drink tea.
Interrogative: Can't I drink tea?
18) We can't drink beer.
Interrogative: Can't we drink beer?
19) I can't drive for two months.
Interrogative: Can't I drive for two months?
20) The clown can act.
Interrogative: Can the clown act?