writing

The sentence is grammatically correct, but its meaning is somewhat uncertain without the full context, and it may not express what you mean to say. Can you explain in other words what you are trying to express, especially with the word "should"?

GPYThe sentence is grammatically correct, but its meaning is somewhat uncertain without the full context, and it may not express what you mean to say. Can you explain in other words what you are trying to express, especially with the word "should"?

This is an answer to the following question.
Q.. His father's advice was sound.
It was what it sh

thein lwinThis is an answer to the following question.Q.. His father's advice was sound. It was what it should be.

"His father's advice was sound" is a statement, not a question. It is not clear that the second statement is an appropriate response to the first.

thein lwinThis is an answer to the following question.Q.. His father's advice was sound.

What you label a question (with Q) is not a question. Maybe you meant Was his father's advice sound?

I'm inclined to want It was what is should have been as the answer.

CJ

GPY thein lwinThis is an answer to the following question.Q.. His father's advice was sound. It was what it should be."His father's advice was sound" is a statement, not a question. It is not clear that the second statement is an appropriate response to the first.

Can I rewrite the sentences into one sentence like
this? His father's advice was as sound as

thein lwinCan I rewrite the sentences into one sentence like this? His father's advice was as sound as it shouldbe.

Possibly, or "as sound as it should have been" may be better. However, I am still not really any clearer about what you are trying to say, or whether this wording properly expresses it. As I said in the first reply, the meaning seems uncertain.