Jawaban:

21. ( + ) These people clean their neighborhood every month.

( - ) These people do not clean their neighborhood every month.

( ? ) Do these people clean their neighborhood every month?

22. ( + ) People often visit the park on Sunday.

( - ) People do not often visit the park on Sunday.

( ? ) Do people often visit the park on Sunday?

23. ( + ) Lia always makes dinner every day.

( - ) Lia does not always make dinner every day.

( ? ) Does Lia always make dinner every day?

24. ( + ) It usually rains a lot in January.

( - ) It does not usually rain a lot in January.

( ? ) Does it usually rain a lot in January?

25. ( + ) A mango tree usually produces hundreds of fruits.

( - ) A mango tree does not usually produce hundreds of fruits.

( ? ) Does a mango tree usually produce hundreds of fruits?

Penjelasan:

The Formula of Simple Present Tense:

Kalimat Positive (+)  :

- Verbal     :  Subject + Verb1/Verb1+s/es + Object

 - Nominal  :  Subject + Tobe (am, is are) + Object

Kalimat Negatif (-)    :

- Verbal     :  Subject + do/does not +Verb1 + Object

- Nominal  :  Subject + Tobe (am, is are) +NOT + Object

Kalimat Interrogative (?)  :

- Verbal    :  Do/Does + Subject + Verb1 + Object + ?

- Nominal :  Tobe (am, is are) + Subject + Object + ?

Jawaban di atas mengikuti Formula kalimat Verbal dan untuk bentuk kalimat verbal negatif Auxiliary Verbs seperti kata Do not dan Does not dalam bentuk negatif bisa disingkat menjadi bentuk Contraction forms yaitu: Don't dan Doesn't.

Kalimat Nominal contohnya:

(+) We are students.

(-) We are not students.

(?) Are we students?

Dalam kalimat nominal, bentuk kata kerja To be (is / am / are) dalam bentuk negatif is not dan are not juga bisa disingkat menjadi bentuk Contraction forms yaitu: isn't dan aren't namun am not tidak bisa disingkat.

Semoga membantu ya.