Learn Portuguese (Portugal): Esta cor é feia, mas esse vestido é lindo. - This color is ugly, but that dress is beautiful.

Esta means "this" (something close to the speaker), while esse means "that" (something close to the listener, or just a bit further away). The speaker might be holding a color sample in their hand but pointing at a dress the other person is looking at.

Why does the word for "this/that" change from esta to esse?

These words are demonstrative determiners, and they must match the gender of the noun they describe. Cor (color) is feminine, so we use the feminine word for "this", which is esta. Vestido (dress) is masculine, so we use the masculine word for "that", which is esse.

Wait, is the word cor feminine? It doesn't end in an "a".

Yes, it is feminine! While many Portuguese words ending in an "a" are feminine and words ending in an "o" are masculine, words ending in consonants like "r" can be tricky. Cor is a feminine noun you just have to memorize. Notice how the adjective feia (ugly) also ends in an "a" to match it.

Why do we use é here instead of está?

We use é (from the verb ser) because in Portuguese, basic physical traits like being ugly (feia) or beautiful (lindo) are treated as core, permanent characteristics of the object itself. You would only use está (from the verb estar) to describe a temporary state.