Learn Dutch: Haar cijfers op haar rapport zijn uitstekend, vooral voor Engels. - Her grades on her report card are excellent, especially for English.

Vooral acts as a focus adverb meaning "especially" or "mainly". You use it to highlight one specific thing out of a broader group. Here, it emphasizes that out of all her excellent grades, the English grade stands out the most.

Does uitstekend literally mean "sticking out"?

Yes! It comes from the verb uitsteken (to stick out). Just like the English word "outstanding", it is used to describe something that is so good it naturally stands out from the rest.

Is rapport used for any kind of report, like a news report?

In a school context like this sentence, het rapport specifically means a "report card". While it can also mean a formal business or police report, you wouldn't normally use it for a news report or a written school essay (that would usually be het verslag).

Why do we say voor Engels instead of in Engels?

In Dutch, when talking about receiving a grade or mark for a specific school subject, you use the preposition voor (a grade for English). However, if you were talking about your general skills, you would say you are good in a subject (goed in Engels).