Quan algú truca, apunta el seu número a l'agenda.

in

Breakdown of Quan algú truca, apunta el seu número a l'agenda.

• quan: when
• trucar: to call
• l'agenda: the planner

Questions & Answers about Quan algú truca, apunta el seu número a l'agenda.

Why is apunta used here instead of apuntes or apunti?

Here apunta is the affirmative imperative for tu of the verb apuntar.

• apuntar = to write down / note down
• (tu) apunta = write it down
• (vostè) apunti = write it down (formal singular)
• (tu) apuntes is not the affirmative command form

For regular -ar verbs, the affirmative tu command has the same form as the 3rd person singular present:

• ell/ella apunta
• (tu) apunta

So the sentence is giving an instruction: When someone calls, write down their number in the address book / contacts list.

Could apunta also mean he/she writes down?

Yes. By itself, apunta can mean either:

• he/she writes down
• write down! (informal singular command)

Catalan often has this kind of overlap. You understand which meaning is intended from context.

In this sentence, the most natural reading is the imperative: it sounds like an instruction or piece of advice.

Why are the verbs in the present tense?