Il telefono vibra sul tavolo.

In Italian, most singular nouns require a definite article.

• Il is the masculine singular definite article (equivalent to English the).
• Unlike English, which can drop the article in statements like “Children play outside,” Italian almost always keeps it in front of nouns.

The verb ending must agree with the subject.

• Il telefono is a third-person singular subject.
• Verbs ending in -are take -a for third-person singular in the present simple (e.g. vibra).
• If the subject were plural (e.g. i telefoni), the form would be vibrano.

Italian often employs the simple present for both habitual and ongoing actions.

• To stress that something is happening right now, you can use the progressive construction:
  • Il telefono sta vibrando sul tavolo (literally “the phone is vibrating on the table”).
• However, the simple present vibra is perfectly natural to say “the phone vibrates” or “the phone is vibrating.”

They are two distinct verbs describing different actions of a phone:

• vibrare = to vibrate or buzz (often when the phone is on silent).
• squillare = to ring (when the phone uses its ringtone).

Sul is a mandatory contraction of the preposition su (on) + the definite article il (the).

• su
  • il = sul
• Similarly:
  • su + lo = sullo
  • su + la = sulla
  • su + i = sui
  • su + gli = sugli
  • su + le = sulle

No. In standard Italian you must contract the preposition with the article.

• All combinations of a, da, di, in, su with definite articles are contracted (e.g. dal, dalla, nell’, sulla).

Italian is a pro-drop language: the verb ending already indicates the person and number.

• Adding lui or esso would be redundant and sound odd.
• The ending -a tells us it’s third-person singular without an explicit pronoun.

Yes. Italian word order is fairly flexible.

• Fronting sul tavolo places emphasis on the location (“It’s on the table that the phone vibrates”).
• The neutral order remains Il telefono vibra sul tavolo, but both are correct.

Telefono is masculine.

• Most Italian nouns ending in -o are masculine (e.g. libro, amico, ragazzo).
• The article il also signals that it’s masculine singular.