To use "was" or "were" in a sentence, you need to consider the subject and the past tense of the verb. Here are some examples:
- I was happy yesterday.
- She was running in the park.
- They were playing soccer.
- He was a teacher before he retired.
- We were studying for the exam all night.
- The book was on the shelf yesterday.
- The cats were sleeping on the couch.
- You were late for the meeting.
- It was raining all day yesterday.
- The flowers were blooming beautifully in the garden.
In these examples, "was" is used with the pronouns "I," "she," "he," and "it," while "were" is used with the pronouns "they," "we," and "you," as well as plural nouns like "cats" and "flowers." Remember to choose the correct form based on the subject and the past tense of the verb.