I'd like to have a clarification on a type of sentence structure.

I was asked to write and share my thesis statement with the class. The sentence was written in this structure "It was not until....+ (main clause)" with the inversion of the subject and the verb in the main clause like this:

"It was not until..........did I realize......"

the instructor stuttered over the inversion part twice and self-corrected it to say ".......that I realized.......", so my question is: Was I wrong? I had thought this structure was pretty common. I tried to google it but couldn't find examples to back me up. So Have I been wrong the whole time?

Anxiously waiting for any help/answer. Thanks a lot

Hi Raen
Raen"It was not until..did I realize.."
Your instructor is right. The inversion is only used if a sentence begins with the words "Not until". In other words, there can be no other words before "Not until". Adding "It was" to the beginning means there will be no inversion.

You can use these formats, for example:

- It was not until X that I realized Y.
- Not until X did I realize Y.
Ahhh I see, Yankee. Thank you so much. Emotion: smile
I think both sentences are right.