Instruktorka przypomina mi też o pasie bezpieczeństwa, zanim uruchomię silnik.

Instruktorka is the feminine form of instruktor (instructor).

So:

• instruktor = a male instructor
• instruktorka = a female instructor

Since the sentence refers to a woman, Polish uses instruktorka.

Mi means to me.

In this sentence:

• Instruktorka przypomina mi... = The instructor reminds me...

Polish uses the dative case for the person receiving the reminder:

• mi = to me
• ci = to you
• mu = to him, etc.

Why not mnie?
Because mi is the normal unstressed short form, and it sounds most natural here. Mnie is the fuller form and is used more for emphasis, contrast, or after some prepositions.

So:

• przypomina mi = neutral, natural
• przypomina mnie = incorrect here

The verb przypominać can be used in different patterns.

Here it means to remind someone about something, so the pattern is:

• przypominać komuś o czymś

That gives us:

• komuś = to someone → mi
• o czymś = about something → o pasie bezpieczeństwa

So:

• Instruktorka przypomina mi o pasie bezpieczeństwa
  = The instructor reminds me about the seat belt

This is a very common structure in Polish.

After the preposition o in the meaning about/regarding, Polish uses the locative case.

So:

• pas = belt
• o pasie = about the belt

That is why pas changes to pasie.

The full phrase is:

• pas bezpieczeństwa = seat belt / safety belt
• o pasie bezpieczeństwa = about the seat belt

Notice that only pas changes to locative here.
bezpieczeństwa stays in the genitive, because it depends on pas in the expression pas bezpieczeństwa.

That is just a normal Polish noun pattern.

Polish often expresses combinations like this with:

• main noun + dependent noun in the genitive

So:

• pas bezpieczeństwa = literally belt of safety
• natural English meaning = seat belt / safety belt

Other similar examples:

• szklanka wody = glass of water
• nauka języka = learning of a language / language learning

So although it sounds unusual word-for-word in English, it is completely normal in Polish.

Też means also or too.

In this sentence:

• Instruktorka przypomina mi też o pasie bezpieczeństwa... = The instructor also reminds me about the seat belt...

Its position is flexible, because Polish word order is more flexible than English word order. Here też naturally attaches to the idea of also reminds me.

You could move it in some contexts, but the given version sounds natural.

Because zanim means before, and here the sentence refers to a specific action that will happen after the reminder: starting the engine.

The verb uruchomić is perfective, and its present-tense forms usually refer to the future.

So:

• uruchomię literally looks like present tense
• but with a perfective verb it means I will start

Therefore:

• zanim uruchomię silnik = before I start the engine

Using uruchamiam would suggest an ongoing/repeated present action and would not fit as well here.

Formally, it is the present-tense form of a perfective verb, but in meaning it refers to the future.

This is a key Polish pattern:

• imperfective present = true present
  
  • uruchamiam = I am starting / I start
• perfective present form = future meaning
  
  • uruchomię = I will start

So in practical terms, you should understand uruchomię here as I will start.

Because the two verbs describe different kinds of actions.

1. przypomina

This is from the imperfective verb przypominać.
It is used here for something habitual or repeated:

• the instructor reminds me

This sounds like a regular thing that happens during lessons.

2. uruchomię

This is from the perfective verb uruchomić.
It refers to a single completed action in the future:

• before I start the engine

So the contrast is natural:

• przypomina = ongoing / repeated situation
• uruchomię = one completed action that will happen

It is in the accusative — it just happens to look the same as the nominative.

The verb uruchomić takes a direct object, so silnik is in the accusative:

• uruchomić co? → silnik

But for many masculine inanimate nouns in Polish, the singular accusative has the same form as the nominative.

So:

• nominative: silnik
• accusative: silnik

That is why there is no visible change.

Yes — literally it means she reminds me about the seat belt.

But in context, the intended meaning is usually very clear:

• she is reminding me to fasten / wear / check the seat belt

Polish often uses remind someone about something where English might use:

• remind me to put on my seat belt
• remind me about the seat belt

So the Polish wording is a little broader literally, but very natural.

Because zanim uruchomię silnik is a subordinate clause:

• before I start the engine

In Polish, subordinate clauses are usually separated by a comma.

So:

• Instruktorka przypomina mi też o pasie bezpieczeństwa, zanim uruchomię silnik.

That comma is standard and correct.

Yes. Polish word order is more flexible than English word order, because cases show grammatical relationships.

For example, you could also hear variations like:

• Instruktorka też przypomina mi o pasie bezpieczeństwa, zanim uruchomię silnik.
• O pasie bezpieczeństwa instruktorka też mi przypomina, zanim uruchomię silnik.

But the original sentence is natural and neutral.

The chosen order puts the information in a smooth, standard way:

1. who does it
2. what she does
3. to whom
4. also
5. what about
6. before what action

So even though other orders are possible, the original is a good everyday version.