SmarpanGamt wrote:Any theory of grammar should answer three basic questions: what constitutes knowledge of grammar, how it is acquired, and how it is put to use.

(A) how it is acquired, and how it is put to use
(B) how is knowledge of grammar acquired, and how put to use
(C) how it was acquired and put to use
(D) its acquisition and putting to use
(E) how its knowledge is acquired, and how it is put to use

Please explain each of the choices. OA A. what is wrong with E ?

The issues:

1. Colon:

We should have the idea of using colon. when we use colon, we should bear in mind the following rules:

1.1. Clause + colon.
1.2. Colon (:) List of things, list of clauses, list of phrases etc.

Now, the things that will be use in the list MUST be grammatically parallel.

Now, come to the sentence:

B. How put to use is problematic because it does not have subject; therefore it is fragment. Besides, the X, Y, and Z after colon is a list of clauses, but "how put to use" is not a clause. --Eliminate it.

C. how it was acquired and put to use" is wrong for two reasons:

1. No comma should be used in case of list of two things. Example---X and Y, not X , and Y; and not X, Y.
2. It failed to become an element of the list of three clauses.

D. D is wrong for the same reason as it is in C.

E. "its knowledge" is problematic. It changes the intended meaning of the sentence.

Answer is A.

Good explaination. Thank you

What " It" refers to. Knowledge of Grammer or theory of Grammer. I suppose option "A" changes the meaning.