In Kash, contrafactual sentences use _kendi......., kendi...._. roughly = if.....then. The two clauses can't be reversed, as they can in Engl. and I think other SAE languages. The verbs are in present tense:

kendi me hahanga, kendi te malolan
"if" me you-pay, "then" you I-protect 
Best Engl: If you (should/would/were to) pay me, I would protect you.
There is no certainty ( in fact there's doubt) that either action will take place. 

The only other tense that's possible here is the pres.perfect, in both clauses:
kendi me mende hahanga, kendi te mende malolan
If you had paid me, I would have protected you.

In this case you can also start the protasis with _kendipun_ 'if only....'  You could say the protasis in isolation--  "kendipun te mende halolan...." If only I'd protected you.... :" (implied: [kendi, then] something bad would not have happened to you.)

A lot of people mistakenly use plain old "pun" 'if', with future tense in both clauses, but definitely in the apodosis:

pun me hahanga(to), te malolando
If you (will) pay me, I will protect you.
In this case, the two clauses can be reversed: te malolando pun me hahanga(to).

But in this case, there is a certain definiteness, and an actual promise to protect you, hence the future tense in the apodosis. It's also a little bit's the sort of thing the neighborhood crime boss might say to a shopkeeper, or a bully to his victim.

Even more brusque and threatening if he leaves out the "pun". 

Prevli would use irrealis mode in the first case (conditional tense in both clauses I think), indicative future tense in the second case, with the same sense of commitment, but maybe not so threatening..........

Not at all sure about Gwr......we haven't gotten that far with the syntax... I suspect they'd have to use a particle expressing doubt or something. WWCD?  (what would Chinese do?)