Questions & Answers about Meu olho dói.
Because olho is a masculine singular noun. In Portuguese, the possessive has to agree with the noun:
- meu olho = my eye
- minha mão = my hand
So meu goes with masculine singular nouns, and minha goes with feminine singular nouns.
Dói is the third-person singular form of the verb doer = to hurt / to ache.
The subject here is meu olho = my eye, which is singular, so the verb must also be singular:
- Meu olho dói. = My eye hurts.
- Meus olhos doem. = My eyes hurt.
Even though the person feeling the pain is I, the grammatical subject is my eye.