西班牙文既esto,ésta,éste都解this但有咩唔同

Wrong, you simply can't compare Portuguese to Spanish, because they
are different languages no matter what.

esto means 'this' , e.g. que es esto? - What is this?

esta is more difficult, because it can be from the verb, estar,
which means a changed condition or state as opposed to identity or nature, which is normally expressed by ser. However, it can also be used when the emphasis is on the speaker's perception of things, of their appearance, taste, etc. The examples given below should be contrasted with those to be found in 'Ser'.

Therefore, when you say esta, there are several ways to say it.

1. Esta muy simpatico. ( He is very nice)
2. Donde esta el colegio? ( Where is the school?)
3. Esta cerca de mi casa. ( It is near my house)

As you can see ESTA can be used to describe something and used for a location.

Este is first, third person subjunctive tense. Used for both gender.

我不識西班牙文,但試從葡文方面回答你這個問題,雖然葡文同西班牙文不是同一種語言,但兩者極相似

esto=isto(葡文,純個人猜測) 這個字正如你所講屬中性(noun),是當名詞咁用,
如: 這是一個人, this is a man.

ésta=esta(葡文,純個人猜測)這個字用於男仔字, 陽性名詞, 是當形容詞咁用,後面一定要跟陽性名詞
如: 這個男人是人

éste= este(葡文,純個人猜測),這個字用於女仔字,陰性名詞,同樣當形容詞咁用,後面一定要跟陰性名詞
如: 這個女人是人

希望可以回答到你的問題