A lot of students misuse these two lexical verbs by using "borrow" in a right context for "lend" and "lend" instead of "borrow".
To make it clear, it is for a giver to lend while it is for a receiver to borrow.
When you as a giver is sending something out to a person without getting paid or receiving something different in return but with an aim of collecting the exact what you give to the person back after a period of time, in that case you "lend". Its past tense is 'lent'.
Consider:
1. John, please lend me your motorcycle for two hours.
2. When will you return it if I lend you $10,000 now?
Whereas, if you as a receiver intends to receive something from someone else with an aim to return it after some time, you "borrow".
Consider:
3. John, please can I borrow your motorcycle for two hours?
4. I will return it in two days time, if I borrow the $10,000 from you.
Therefore, it is incorrect to say:
5. Please, borrow me your pen until tomorrow evening - X Incorrect
Or
6. Let me lend your computer for tonight. - X Incorrect
Consider the following for practice:
1. The doctor and his wife promise to ............... the man their second car to travel.
            A .    lent
            B.     Borrowed
            C.     Borrow
            D.     Lend
2. Madam Smart used to ............. money from me almost every time.
            A.    borrowed
            B.    lending
            C.    borrow
            D.    vorrows
3. I ............ Mr. Smart my most favorite car yesterday by has failed his promise to return it today.
            A.     lent
            B.     borrow
            C.     rent
            D.     lend