Is it necessary to use the preposition 'to' in the following sentence or we can omit it?
We can pay to Boris tomorrow.
By omitting it'll be:
We can pay Boris tomorrow.
Is it necessary to use the preposition 'to' in the following sentence or we can omit it?
We can pay to Boris tomorrow.
By omitting it'll be:
We can pay Boris tomorrow.
You can safely omit the preposition. In fact, you should.
You would include the preposition only if you had another direct object after pay, such as money, the debt, the sum owing or similar.
So it's either:
We can pay Boris tomorrow
or
We can pay the money to Boris tomorrow.
Alternatively, you could reverse the direct and indirect objects to read:
We can pay Boris the money tomorrow.
We can pay to Boris tomorrow.
When I began reading this, my brain assumed you were trying to say "we can pay (money) (in order) to (do something)", as in the phrase "pay to play":
Also called 'Pay to Play' A phrase used for a variety of situations in which money is exchanged for services or the privilege to engage [play] in certain activities
https://www.collinsdictionary.com/submission/14425/Pay-for-Play
It honestly took me a few seconds of wondering what kind of activity "Boris-ing" is before I understood what you meant.
So while you can pay £100 to drive a racing car, you should say "we can pay Boris tomorrow".