usage of never..

[rafeezah]

i never knew my fiance befor my engagment..
should we always use past with never?

 

[Mohammadhelmi]

'never' is formally used with the present perfect simple
1. I have never seen the film.

'never' is also used with the present simple
1. i never go to the USA.

 

[Barb_D]

Something from the past changed (also in the past): I had never met him before the night he asked me to marry him.

Something from the past is changing now: I have never met him before. I can't wait. (As I stand waiting to meet him.)

Something from the past that cannot be changed now:
I never met my birth mother, and now that she's dead, I never will.

Something from the past can still possibly be changed in the future: I have never met him.

 

[Abstract Idea]

i never knew my fiance befor my engagment..
should we always use past with never?

"Never" is an adverb, so you can use it with other tenses as well.
It is not restricted only to past tenses.

I never sleep more than eight hours a day.
I'll never learn English. (just kidding)
They should never say something like that.
Never say never.
He was never studying English.

Take a look at other examples here: never: Definition from Answers.com

Not a native speaker

 

[Raymott]

i never knew my fiance befor my engagment..
should we always use past with never?

In this case, you should say, "I didn't know my fiance before my engagement". If you knew him/her once, you know him/her. "Never" doesn't apply.
Of course, if you mean "knew" in the Biblical sense, then your sentence is correct.