Learn Hardcore Italian: Non dovresti dimenticarti di chiudere la finestra prima di uscire. - You shouldn’t forget to close the window before going out.

Italian uses dovresti (the conditional of dovere) to give advice—you should. Devi (present of dovere) is stronger—you must. So Non dovresti dimenticarti… means you shouldn’t forget, which is softer than Non devi dimenticarti… meaning you must not forget.

What role does non play in Non dovresti?

Non negates the verb. Placing non before dovresti turns you should into you shouldn’t. In Italian, the negative particle non always precedes the conjugated verb it negates.

Why is the verb reflexive (dimenticarti) and why is ti attached to the end?

Dimenticarsi is the reflexive form used for “to forget (something).”
Ti is the 2nd-person singular reflexive pronoun (“yourself/you”).
When you have an infinitive (dimenticare) plus a pronoun (ti), Italian attaches it to the end: dimenticarti = “to forget yourself.”
Without the reflexive, you could say dimenticare, but dimenticarsi is very common for “forget to do something.”

Why do we need di after dimenticarti? Could you say dimenticarti chiudere?

Certain verbs in Italian (like dimenticarsi, pensare, cercare, etc.) require di + infinitive. The pattern is dimenticarsi di fare qualcosa. You cannot drop di; you must say dimenticarti di chiudere, not dimenticarti chiudere.

Can I drop the reflexive pronoun and say Non dovresti dimenticare?

Yes. Non dovresti dimenticare di chiudere la finestra… is grammatically correct and means the same. Both dimenticare and dimenticarsi di can be used with this meaning, though dimenticarsi di is especially common in spoken Italian.

Why is la finestra using the definite article? Would you ever omit it?

In Italian, definite articles are used with body parts and common objects even when ownership is clear. You say chiudere la finestra, not just chiudere finestra. You omit the article only in very general or abstract contexts, but here you need la.

Why is prima di uscire using di + infinitive instead of a subjunctive clause?

When both actions share the same subject (“you”), Italian prefers prima di + infinitive: prima di uscire = “before going out.” If the subject changes, you’d use prima che + subjunctive (e.g. Prima che tu esca…).

Why is there no subject pronoun like tu? How do we know who is being addressed?

Italian usually drops subject pronouns because verb endings (here -esti in dovresti) indicate the person. Context clarifies that you’re talking to “you,” so tu is unnecessary.

Could I use the imperative instead of the conditional, like Non dimenticarti di chiudere…?

Absolutely. Non dimenticarti di chiudere la finestra prima di uscire is a direct negative command (“Don’t forget to close…”). The conditional Non dovresti… is softer, more like giving advice.

What happens if I omit non? Does Dovresti ricordarti work here?

Without non, Dovresti dimenticarti di chiudere… literally means you should forget to close…, which is the opposite of what you want.
To advise someone to remember, switch to ricordarsi: Dovresti ricordarti di chiudere la finestra prima di uscire = you should remember to close the window before going out.