Learn Hardcore Greek: Η δασκάλα προτείνει να διαβάσουμε λιγότερο σήμερα. - The teacher female suggests that we read less today.

It introduces a subordinate clause in the subjunctive after a verb of suggestion (προτείνω). It signals that the action is desired/possible, not a simple statement of fact. It often corresponds to English ideas like “that we (should) …” but να itself is not translated.

After να, you use a subjunctive form of the verb.
Negation in a να-clause uses μη(ν), not δεν.

Why is it διαβάσουμε and not διαβάζουμε after να?

Aspect.

να διαβάσουμε is the perfective (aorist) subjunctive: a single, bounded action (“read less” as a one-off for today).
να διαβάζουμε is the imperfective (present) subjunctive: ongoing/habitual action (“be reading less” over time). With σήμερα, the perfective makes the natural “for today” suggestion.

What person/number is διαβάσουμε, and where is “we”?

διαβάσουμε is 1st person plural (“we”). Greek is a pro‑drop language, so the subject pronoun (εμείς) is usually omitted unless you want to emphasize it.

Can I use ότι instead of να after προτείνει?