Rumus kalimat positif negatif interogatif dari present continous

(+) S + tobe + v-ing
(-) S + tobe + not + v-ing
(?) tobe + s + v-ing

(+) Subject + to be (is/am/are) + Verb ing
(-) Subject + to be (is/am/are) not + Verb ing
(?) To be (is/am/are) + subject + Verb ing?
     Yes, Subject + to be (is/am/are)
     No, Subject + to be (is/am/are) + not

untuk subject tunggal (termasuk pronoun he, she, it), to be nya is
untuk subject jamak (termasuk pronoun you, they, we), to be nya: are
untuk subject I, to be nya: am