Question

I knew that once i could write like an educated man there would be no limit to what I could achieve. [FRAME Wh type question to get the answer--That once I could write like an educated man there would be no limit to what I could achieve.]

Answer 1

$Hey...$

Here is your answer...

Assumed answer :

That once I could write like an educated man there would be no limit to what I could achieve.

Wh- question :

What did you know ?

Explanation :

We used the verb form "know" with "did" because it explains about something that we have been knowing.

Hope it helps..