Questions & Answers about Этот бутон ещё закрыт.
Because бутон is a masculine singular noun.
In Russian, demonstratives like this must agree with the noun in gender, number, and case:
- этот = masculine singular
- эта = feminine singular
- это = neuter singular
- эти = plural
Since бутон is masculine singular, the correct form is этот бутон.
It is in the nominative case.
That is because бутон is the subject of the sentence — the thing being described as closed.
So the structure is basically:
- Этот бутон = the subject
- ещё закрыт = what is being said about it