Choose the correct negative sentence in present perfect.

1.

• I have not phoned the helpline yet.
• I has not phoned the helpline yet.
• I have not yet phoned the helpline.

2.

• She has not skating on a lake in winter yet.
• She have not skated on a lake in winter yet.
• She has not skated on a lake in winter yet.

3.

• They has not learned the formulas, so they will probably fail the test.
• They have not learn the formulas, so they will probably fail the test.
• They have not learned the formulas, so they will probably fail the test.

4.

• He have not tidied up his desk yet.
• He has not tidy up his desk yet.
• He has not tidied up his desk yet.