1. Jake has not bought souvenirs for friends.
To form a negative sentence in the present perfect tense, we need to use the auxiliary verb "have" in its negative form, which is "have not" or "haven't." We then follow it with the past participle form of the main verb "bought." Since the main verb "buy" is regular, its past participle form is the same as its base form. Finally, we add "souvenirs for friends" to complete the sentence.
2. I have not met my friend today.
Again, we start with the negative form of the auxiliary verb "have," which is "have not" or "haven't." The main verb in this sentence is "meet." In the present perfect tense, the past participle form of "meet" is "met." Finally, we include "my friend today" to complete the sentence.
3. I have not pulled a muscle.
Similarly, we begin with the negative form of the auxiliary verb "have," which is "have not" or "haven't." The main verb in this sentence is "pull." In the present perfect tense, the past participle form of "pull" is "pulled." We then add "a muscle" to finish the sentence.
It is important to note that in negative sentences, we do not use contractions like "don't" or "can't." We need to write the full forms of the auxiliary verb "have" and the negative particle "not." Additionally, full stops are not needed in this exercise as they are already provided.
1 Jake has not bought souvenirs for friends.
2 I have not met my friend today.
3 I have not pulled a muscle.