There are two main uses of 'had' 1. The past tense of 'have' I had three dogs at one time. 2. Past perfect - to indicate that something happened or was completed in the past before something else. I had been to Europe three times before my last trip There are other uses, but these are the main ones.

The word "had" is past tense of the verb "to have". Have can mean "to own", to hold in possession, to hold in one's use, and many other uses. EXAMPLES: I have a red car. I have a bucket of water, and will water the flowers. I have to go to the store. etc. Past tense: Yesterday I had a party for my little girl. Last week I had to go to the hospital.

There is another use of the word "had" that is very common. It is used as the past tense of the concept of "must." It can be used in place of "was required to," "was necessary for me to," or "needed to." Here are some sample sentences to complement the answers above: I had to buy a regular soda, because they had no diet soda. I had to call the doctor because I was very sick. The student had to finish their test within one hour. He had to drive very far in order to attend the concert, which was in another city. The restaurant's chef had to tell the customer that they could not have their favorite meal, because they did not have all of the ingredients that day.