My friend gave me a Russian exercise to translate from English
"Dogs don't bite without barking first."

I translated it as:
"Соба́ки не куса́ют без ла́ять пре́жде"

She corrected me to:
Соба́ки не куса́ются без пре́жде ла́я

I was wondering what's the difference between ла́ять, and ла́я...I knew ла́ять is the non-inflected form, but I only found out today that "ла́я" is the "present/future tense gerund"

i.e.


See where it says "present/future tense gerund" in the middle? That was what she corrected me to.

So that leads me to further questions. If I wanna say "Need to look first, then buy," I really should say:
На́до пре́жде смотря́, потом купя́
As opposed to
"На́до пре́жде смотре́ть, потом купи́ть"


Problem is that not all verbs have this "present/future tense gerund".... Like the word поня́ть. So in the case of this word I just leave it as "поня́ть"?

На́до пре́жде поня́ть, потом пиша́

The same with the word "пить". No ""present/future tense gerund" either:

Э́то ва́жное пить во́ду.

The word "кушать" however does have a "present/future tense gerund"... It is "ку́шая"...so in this case, I just write "ку́шая"? :

Э́то ва́жное ку́шая хоро́шую пищу

Would appreciate feedback...thank you