给定一段英文文本，检查其语法错误并提供修改建议。
I has a cat yesterday.
Corrected sentence: I had a cat yesterday.

Explanation: 
- Use "had" instead of "has" because the verb needs to be in the past tense to indicate an action that happened in the past.
- The word "a" is correct, but it's more common to use "one" instead of "a" before the noun "cat." So, the sentence could also be written as "I had one cat yesterday."