[Grammar] Infinitive and gerund

[Checkmate]

"It's better to not know this"

or

"It's better to not knowing this"

or might be

"It's better not to know this"

Which one should I say?

 

[Rover_KE]

1 is possible, 2 is wrong and 3 is best.

 

[Checkmate]

1 is possible, 2 is wrong and 3 is best.

How about "it's better if you do not know this"?

 

[MikeNewYork]

That works.

 

[Matthew Wai]

2 is wrong

Would 2 be right if 'to' were omitted?

 

[MikeNewYork]

Yes.