In the sentence, "Did you buy that car you were looking at?", the verb is the two word phrase "did ... buy". This is technically the "intensive past" tense of "buy", but it could more reasonably be called the "interrogative past" tense, since it is used more often to ask questions than to show intensity of feeling. If the tense was used to show intensity, the two words in it would usually be consecutive, rather than divided as in the sentence shown. An example of this would be "He did buy that car, despite all its problems about which I warned him."
The past participle of buy is bought.
Will buy. -- I will buy the bread on my way home am/is/are going to buy -- They are going to buy some ice cream before they come here am/is/are buying -- He is buying a new car next week
Looking for is present tense.
Will buy
The past tense of look IS LOOKED.
Past perfect tense - I had saved. Present perfect tense - I have saved.
The past tense of "has" is "had." For example, "He has a car" changes to "He had a car."
You might buy a new car if it is a cool looking car. That's all i can think of!
the present tense for buy is bought :]
Yes, "will buy" is the future tense of the verb "buy".
I/he/she/it was looking. You/we/they werelooking.
I/you/we/they buy. He/she/it buys.