Question

My mother__________English for every twenty years now.

A.has been teaching B.had been teaching C. was teaching D. have been teaching

Answer 1

A

Step-by-step explanation:

Singular subject

Answer 2

a) has been teaching.

Step-by-step explanation:

My mother has been teaching English for the past two decades.

Both has and had been applied in the case of continuous tense, such as present perfect continuous and past perfect continuous, which makes it intriguing.