Questions & Answers about Ese traje gris es elegante.
Both are demonstratives, but they point to different degrees of distance.
- este traje = this suit (closer to the speaker)
- ese traje = that suit (a bit farther away, or already mentioned)
So ese is the masculine singular form that goes with traje.
In Spanish, a demonstrative like ese already works as a determiner, so you normally do not add el before the noun.
- ese traje = that suit
- not ese el traje
It works like English: you say that suit, not that the suit.
Nouns in Spanish have grammatical gender, and traje is a masculine noun:
- el traje = the suit
Because it is masculine singular, the demonstrative must match it:
- ese traje
- not esa traje
This is grammatical gender, not biological gender.