Il traffico aumenta la sera.

Traffic increases in the evening.

Breakdown of Il traffico aumenta la sera.

• la sera: the evening
• il traffico: the traffic
• aumentare: to increase

Questions & Answers about Il traffico aumenta la sera.

Why is traffico preceded by il?

In Italian, most common nouns need a definite article even when you speak of them in a general sense. Il traffico means “traffic” in general. In English you often drop the article (“Traffic increases…”), but in Italian the article is mandatory with singular count and mass nouns used generically.

What form is aumenta and how does it relate to aumentare?

Aumenta is the third-person singular present indicative of the verb aumentare (“to increase”). The full present-tense conjugation is:
io aumento
tu aumenti
lui/lei aumenta
noi aumentiamo
voi aumentate
loro aumentano
Here traffico is the subject, so we use aumenta (“it increases”).

Why is the sentence in the present tense instead of past or future?

The present tense in Italian often expresses habitual actions, general truths, or recurring situations. Saying Il traffico aumenta la sera conveys that traffic regularly or typically increases in the evening. If you used past (è aumentato) or future (aumenterà), you’d change the meaning to one specific event or a prediction.

Why does sera take the article la here? Could you say sera without it?

Times of day in Italian normally take the definite article: la sera, il mattino, il pomeriggio, etc. You cannot drop the article and just say sera in this position; it would sound ungrammatical. The article turns the noun into an adverbial time expression meaning “in the evening.”

Could you use a prepositional phrase like di sera instead of la sera?

Yes. Il traffico aumenta di sera is also correct and means essentially the same thing.
Nuance:

• la sera focuses on “the evening” as a specific time slot.
• di sera emphasizes “during evenings” more abstractly.
  In everyday use they’re interchangeable here.

Can I change the word order, for example putting the time expression first?

Absolutely. Italian word order is quite flexible. You could say:
La sera il traffico aumenta.
That front-loads the time phrase and adds slight emphasis on “in the evening,” but the neutral order is Subject-Verb-Time as in the original.