Learn Portuguese (Portugal): Esta flor não é tão linda como a floresta. - This flower is not as beautiful as the forest.

To say two things have an equal quality in Portuguese, we use tão followed by an adjective, and then como. Here, that gives us tão linda como (as beautiful as). Because the sentence is negative, the word não simply goes before the verb, giving us não é tão linda como.

Why is the adjective linda (feminine) if the word flor doesn't end in an "a"?

While many Portuguese words ending in a consonant are masculine, a flor (the flower) is feminine. Because the noun is feminine, all the words describing it must match: we use the feminine word for "this" (esta) and the feminine word for "beautiful" (linda).

Why do we use Esta instead of Isto for "this"?

Isto is used for general, unnamed things or abstract ideas, and it never sits directly next to a noun. Since we are pointing to a specific, named object, we must use the demonstrative word that matches the feminine, singular noun flor, which is Esta.

Why use é (from the verb ser) instead of está (from estar)?