Learn Hardcore Portuguese (Portugal): Por favor, lembra-te de trazer o teu computador amanhã. - Please remember to bring your computer tomorrow.

So lembra-te is the correct “remember!” form when you’re speaking informally to one person (using tu). Just lembra without te would normally be understood as “remind (someone)” rather than “remember (yourself)”.

Why is te attached with a hyphen (lembra-te)?

In European Portuguese, in affirmative imperatives, object and reflexive pronouns attach to the end of the verb with a hyphen:

levanta-te – stand up
senta-te – sit down
lembra-te – remember

So lembra-te follows the standard rule: verb + hyphen + pronoun in affirmative commands.
(With negative imperatives, the pronoun goes before: não te lembres.)

Why do we say lembrar-te de trazer? What is the de doing there?

With lembrar-se in the sense of remember to do something, Portuguese uses the preposition de before an infinitive:

lembrar-se de + infinitive

Examples:

Lembra-te de ligar. – Remember to call.
Lembra-te de estudar. – Remember to study.
Lembra-te de trazer o teu computador. – Remember to bring your computer.

So de is required here by the verb pattern; you can’t say ✗ lembra-te trazer.

What’s the difference between lembra-te and não te esqueças?

Both are common and natural, but they have slightly different literal meanings:

lembra-te de trazer… – literally “remember to bring…”
não te esqueças de trazer… – literally “don’t forget to bring…”

In practice:

lembra-te de… sounds like a positive reminder.
não te esqueças de… sounds like a warning not to forget.

Both are fine, and both take de + infinitive:

Não te esqueças de trazer o teu computador amanhã.

Why is it o teu computador and not o seu computador?

In European Portuguese, teu / tua / teus / tuas usually go with tu (informal “you”), and seu / sua / seus / suas usually go with você / o senhor / a senhora (more formal “you”):

tu → o teu computador (informal, friendly)
você / o senhor / a senhora → o seu computador (polite/formal)

Your sentence uses lembra-te, which is the tu form, so the matching possessive is teu:

(tu) lembra-te de trazer o teu computador.

If you changed to a formal style with você, you’d also change the possessive:

(você) lembre-se de trazer o seu computador.

How would I say this politely to a stranger (formal “you”)?

Use the formal imperative and the formal possessive:

Por favor, lembre-se de trazer o seu computador amanhã.

Breakdown:

lembre-se – formal imperative of lembrar-se for você / o senhor / a senhora
se – reflexive pronoun for você
o seu computador – “your computer” in a formal register

This would be appropriate in a professional or respectful context.

How would a Brazilian speaker normally say this?

In Brazil, tu forms exist in some regions, but the most common standard is using você with se or even omitting the reflexive in colloquial speech.

Typical Brazilian options:

More standard/formal:
- Por favor, lembre-se de trazer o seu computador amanhã.
Very common colloquial:
- Por favor, lembra de trazer o seu computador amanhã.
  (They often drop the reflexive se in speech.)

The teu form is less common in much of Brazil unless the region uses tu; seu is more usual there.

Can I move por favor to another place in the sentence?

Yes, por favor is quite flexible in position. All of these are acceptable, with small nuances of emphasis:

Por favor, lembra-te de trazer o teu computador amanhã.
Lembra-te, por favor, de trazer o teu computador amanhã.
Lembra-te de trazer o teu computador amanhã, por favor.

They all sound polite. The version at the beginning or end is especially common.

Can I move amanhã to the beginning? Does the meaning change?

You can move amanhã without changing the basic meaning:

Amanhã, lembra-te de trazer o teu computador.
Lembra-te de trazer o teu computador amanhã.

Both mean the same. Putting amanhã at the start can slightly highlight the time (“Tomorrow, remember to…”), but it doesn’t change the core message.

Why is it trazer and not levar? What’s the difference?

Portuguese distinguishes:

trazer – to bring towards the speaker or the reference point
levar – to take away from the speaker/reference point or to another place

In your sentence, the idea is “bring it (here/with you to where we will be)”:

lembra-te de trazer o teu computador
= remember to bring it with you (to class, to the office, etc.).

If someone is talking about taking it somewhere else, not to where they are, they might use levar:

Lembra-te de levar o teu computador para casa.
– Remember to take your computer home.

How do you pronounce amanhã and lembra-te?

Very approximately (European Portuguese):

lembra-te ≈ LEHM-bra-tə
- lem-: like “lem” in “lemmon” but shorter, nasal m is weak
- -bra: “bra” like in “brah” (short a)
- -te: like a quick “tɨ” (a very short, neutral vowel)
amanhã ≈ ah-ma-NYÃ
- a-: “ah”
- -ma-: “mah”
- -nh-: like “ny” in “canyon”
- final -ã: nasal “an/uh” sound, produced through the nose

The nh in amanhã is always pronounced like English ny in “lasagna”.

Is lembra-te different if I’m talking to a man or a woman?

No. Lembra-te does not change with the gender of the person:

talking to a man: Lembra-te de trazer o teu computador amanhã.
talking to a woman: Lembra-te de trazer o teu computador amanhã.

The verb form and te are the same. What might change is the surrounding context (adjectives referring to the person, etc.), but not this form of the verb.

Is por favor necessary, or is the sentence still polite without it?

The sentence is grammatically complete and not rude without por favor:

Lembra-te de trazer o teu computador amanhã.

However:

Adding por favor softens it and makes it sound more like a request.
Without por favor, it can sound more like a straight instruction or reminder, which is fine in many contexts (teacher to student, parent to child, colleagues who know each other well).