Learn Portuguese (Portugal): O mecânico viu os arranhões em que eu reparei? - Did the mechanic see the scratches that I noticed?

In Portuguese, the verb reparar in the sense of 'to notice' always requires the preposition em (to notice something = reparar em alguma coisa). When you build a relative clause, that required preposition cannot be left at the end of the sentence like it often is in English. It must move right before the relative pronoun que, becoming em que.

Doesn't reparar mean 'to repair'?

This is a classic false friend! While reparar can mean 'to repair' in formal contexts, its most common everyday meaning is 'to notice' or 'to pay attention to' (always followed by em). If you want to talk about fixing the scratches, the mechanic would normally use the verbs arranjar or consertar.

Why are both verbs (viu and reparei) in the Pretérito Perfeito (simple past) instead of the imperfect?

The Pretérito Perfeito is used for specific, completed actions in the past. You noticed the scratches at a specific moment (reparei), and you are asking if the mechanic saw them as a single completed event (viu). If you were asking about an ongoing habit in the past, you would use the imperfect tense.

What is the singular form of arranhões?