6. Past form of ______is not formed by adding d or -ed to the present
O A irregular verb
O 8. linking verb
O c. helping verd
O D. regular verb
7. One of the transformations of the past form of irregular verb is by _______
O A changing the vowel d to t
O B changing the vowel i to a
O c changing the vowel p to t
OD changing the vowel e to i​