给定一段英文文本，检查文本是否符合英语语法和用法规则，并提供任何必要的修改建议。
I has two brother and one sister, they is very smart.
The given text has incorrect grammar and usage. Here's a corrected version with suggestions:

"I have two brothers and one sister. They are very smart."

Suggestion: 

- Use "have" instead of "has" since the subject is "I", which is singular.
- Use "brothers" instead of "brother" since there are two siblings.
- Change "they is" to "they are" to match the plural subject "they".