Answer:
Past simple tense: I <u>was not</u> able to join the celebration last night, Alex.
The activity <u>was </u>really fun.
What <u>happened </u>in the ball last night?
There <u>were </u>a lot of surprises.
A Junior High student <u>presented </u>some magic tricks.
Past perfect tense: I <u>had committed</u> to help grandfather repair his cabinet before you called.
But, if you <u>had joined</u> us, you would have met new friends in our Junior Acquaintance Ball.
Explanation:
When we want to talk about events that took place in the past, we need to use the past tense. Depending on the nature of the event, we can use one out of four types of the past tense:
- Past Simple Tense
- Past Continuous Tense.
- Past Perfect Tense.
- Past Perfect Continuous Tense
The past simple tense is used for completed actions that took place at a specific point in the past. I pointed out five sentences that contain it, but as you can see, there's even more of them in the text you were given.
The past perfect tense is used to talk about actions that were completed before another point in the past. It consists of the auxiliary verb <em>had </em>and the past participle of the main verb. There are only two sentences that contain this tense in the given text.
You can see more information about these tenses in the images attached below: