Learn Portuguese (Portugal): Precisamos de descansar agora.

In Portuguese, the verb precisar (to need) must be followed by the preposition de when you are stating what it is that you need. Even though we just say 'need to rest' in English, Portuguese grammar requires that connecting de.

Is it wrong to leave out the de and just say Precisamos descansar?

In European Portuguese, it sounds unnatural to leave it out, so you should always pair precisar with de. Interestingly, dropping the de before a verb is very common in Brazilian Portuguese, which is why it is especially important to practice using it if you are focusing on the Portuguese spoken in Portugal.

Where is the word for 'we' (nós)?

In Portuguese, the ending of the verb tells you who is doing the action. The ending -amos in Precisamos only ever goes with nós (we). Because the verb itself already makes it perfectly clear who is speaking, the word nós is usually dropped to sound more natural.

Why is descansar left in its original dictionary form?