. . . . . . . . I use your cell phone as I have forgotten mine?

Solution (By Examveda Team)

This question requires understanding the use of modal verbs, specifically the subtle differences in politeness and permission. A modal verb is an auxiliary verb (a helping verb) that expresses possibility, permission, necessity, or ability.

"May" expresses polite permission or possibility. In this context, it's a polite request for permission to borrow the cell phone. The sentence implies a degree of uncertainty – the speaker is asking if it is alright to use the phone.

Why other options are incorrect:
"Do" is a simple present tense auxiliary verb used for questions, but it's too blunt and lacks the politeness required for such a request. It would sound like a demand rather than a request.

"Would" indicates a conditional or hypothetical situation. It suggests a willingness but implies the action is dependent on something else (e.g., "Would you mind if I used your phone?"). This adds unnecessary complication to a simple request for permission.

"Should" implies obligation or advice. It's grammatically incorrect in this context, as using someone else's phone isn't an obligation; it's a request for a favor.

Therefore, "May" is the most appropriate modal verb to express a polite request for permission to use someone else's cell phone.