Question

fill in the blanks with appropriate model verb principal :yes,you can what ....I do for you.​

Answer 1

what can I do for you?

so can is used

Answer 2

$\huge{Answer}$

What can I do for you.

so here we use Can

Modal verbs :

A verb such as can, might, may, ought to, must, that is used before another verb to show that something is possible or necessary is called a modal verb.