To pay: 'I pay in cash' vs. 'I pay on cash'

English as a Second Language English Vocabulary, Grammar and Idioms
1

Hi!
What is correct?

I pay in cash … I pay on cash
I pay in credit … I pay on credit

Batman :roll:

2

Hi,

You pay in cash or by credit.

Alan

3

Hello,
I am Huy, I live in Vietnam, I have learn E since 2000, but my level in English can’t improve better.
Can I ask you about some English Grammar book?

Thank you,