Learn Hardcore Portuguese (Portugal): Durante o outono, o céu fica cinzento mas as estrelas parecem claríssimas à noite. - During autumn, the sky turns grey but the stars look very bright at night.

Both forms are correct, but they have slightly different nuances. Durante o outono emphasizes the duration of the period (“throughout autumn”), while no outono (“in autumn”) is more general and idiomatic. In speech you’ll hear both, but durante adds a sense of “all through that season.”

Why is the verb fica used in o céu fica cinzento instead of é or está?

Ficar in this context means “to become” or “to turn,” so o céu fica cinzento literally means “the sky turns grey.” Using é would state a permanent characteristic (“the sky is grey”), and estar alone wouldn’t highlight the change.

Why is the adjective cinzento masculine and not feminine?

Adjectives in Portuguese must agree in gender and number with the noun they modify. Cinzento is masculine singular because o céu (“the sky”) is a masculine singular noun. If you described a feminine noun, you’d use cinzenta.

In Brazilian Portuguese, would you use cinzento or cinza?

Brazilians commonly use cinza as both noun and adjective (“o céu fica cinza”), though cinzento exists too. In European Portuguese, cinzento is the preferred adjective and cinza is mainly the noun.

Should there be a comma before mas in o céu fica cinzento mas as estrelas...?

Yes. Standard Portuguese grammar dictates a comma before coordinating conjunctions like mas when linking two independent clauses. So you’d normally write:
“Durante o outono, o céu fica cinzento, mas as estrelas parecem claríssimas à noite.”

Why do we use parecem in as estrelas parecem claríssimas instead of são?

Parecer means “to seem” or “to appear,” so it conveys a subjective impression (“the stars seem extremely bright”). Saying as estrelas são claríssimas would simply state as a fact that they are very bright, without the nuance of “it looks that way to me.”

How is the superlative claríssimas formed from claro?

You form the absolute superlative by dropping the final vowel of the adjective and adding -íssimo. So claro → claríssimo. Then you match gender and number: claríssimo (masc. sing.), claríssima (fem. sing.), claríssimos (masc. pl.), claríssimas (fem. pl.). Here as estrelas are feminine plural, hence claríssimas.

Why is there a grave accent in à noite, and what does it mean?

À noite means “at night.” The grave accent on à marks the contraction of the preposition a + the feminine article a (a + a = à). Without the accent, a noite would simply be “the night,” not the time expression “at night.”

Could we also say de noite instead of à noite?

Yes. De noite and à noite both mean “at night,” but with subtle differences. À noite often refers to a general time period (“I like to walk at night”), while trabalhar de noite (“to work night shifts”) emphasizes the activity happening during the nighttime span. In many contexts they’re interchangeable.

Why do we include the article o in o outono when English omits “the” before seasons?

In Portuguese, definite articles are normally used before seasons when combined with prepositions or verbs: o inverno, a primavera etc. English often drops “the” (“in autumn”), but Portuguese grammar requires “o” or “a” to make the phrase sound natural.