Question

Estoy seguro de cuando Manuel (pedir) el teléfono prestado es para hablar con su amigo.

Answer 1

I'm sure when Manuel (borrowing) the borrowed phone is to talk to his friend. 

is the answer.

Answer 2

Answer:

The correct answer is: "pide".

Explanation:

The sentence is ensuring that WHEN Manuel borrows ("pide prestado") the telephone, he actually talks to his friend.

Now, the sentence is referring to the actual present, so the correct form for the verb to conjugate it is present indicative. And as someone is talking about Manuel as a third person singular, then the correct way to conjugate the verb is: "pide".  Note that the verb in English is simple (to borrow) while in Spanish is compose by two verbs: "pide prestado". Either way, in Spanish the verb conjugated is the first one ("pedir"), and the other stays in the participle ("prestado").