Nauczycielka pokazuje, gdzie wstawić przecinek, a gdzie postawić kropkę.

Nauczycielka means female teacher. Polish usually marks gender in job nouns like this:

• nauczyciel = male teacher
• nauczycielka = female teacher

So the sentence specifically tells you the teacher is a woman. If the teacher were male, it would be:

• Nauczyciel pokazuje, gdzie wstawić przecinek, a gdzie postawić kropkę.

Also, nauczycielka is in the nominative singular, because it is the subject of the sentence.

Pokazuje means shows or is showing.

It is:

• 3rd person singular
• present tense
• from the imperfective verb pokazywać

So:

• Nauczycielka pokazuje = The teacher shows / is showing

Polish present tense can often correspond to either simple present or present progressive in English, depending on context.

This is a very common Polish structure: question word + infinitive.

So:

• gdzie wstawić przecinek = where to insert a comma
• gdzie postawić kropkę = where to put a period

English uses where to..., and Polish uses:

• gdzie = where
• wstawić / postawić = infinitive verb

There is no separate word corresponding exactly to English to in this construction. The infinitive itself already carries that meaning.

This whole part acts like an embedded question or indirect question:

• The teacher shows where to insert a comma and where to put a period.

Because Polish often uses different verbs depending on what kind of putting is meant.

Here:

• wstawić przecinek literally suggests insert a comma
• postawić kropkę literally suggests put/set a period

These are partly just natural collocations with punctuation.

A useful way to think about them:

• wstawić = put something into a larger text or structure
• postawić = put/place something at a specific point

With punctuation, Polish often uses verbs in somewhat idiomatic ways, just as English says make a mistake, not do a mistake.

Because both nouns are direct objects, so they are in the accusative case. But their forms behave differently.

1. przecinek

This is a masculine inanimate noun.
For masculine inanimate nouns, the accusative singular is usually the same as the nominative singular.

• nominative: przecinek
• accusative: przecinek

2. kropka

This is a feminine noun.
Feminine nouns ending in -a usually change to -ę in the accusative singular.

• nominative: kropka
• accusative: kropkę

So the sentence needs:

• wstawić przecinek
• postawić kropkę

Because the sentence is about a single completed action: placing each punctuation mark in the correct spot.

In Polish, perfective verbs often express:

• a one-time action
• a completed result
• reaching the endpoint of an action

Here the idea is not the ongoing process of punctuation, but the result:

• put the comma here
• put the period there

That is why wstawić and postawić sound natural.

If you used imperfective forms like wstawiać or stawiać, it would sound more like a repeated, habitual, or process-focused action, which is less natural in this sentence.

A is a coordinating conjunction, but it is not exactly the same as plain English and every time.

In this sentence, it has a contrastive sense:

• gdzie wstawić przecinek, a gdzie postawić kropkę
• where to insert a comma, and where to put a period
• more literally: where to insert a comma, and where to put a period instead / by contrast

Polish a often links two pieces of information while also setting them against each other a little.

So here it feels more structured than simple i (and). It separates two contrasting punctuation choices:

• comma here
• period there

There are two commas, and both are there for grammatical reasons.

1. Comma before gdzie

• Nauczycielka pokazuje, gdzie wstawić przecinek...

In Polish, subordinate clauses are normally separated by commas.
Here gdzie wstawić przecinek... is a subordinate clause introduced by gdzie.

2. Comma before a

• ..., a gdzie postawić kropkę.

The conjunction a is typically preceded by a comma when it connects clauses or clause-like parts.

So the punctuation is fully standard Polish punctuation.

Yes, it often can be, if the meaning stays clear.

For example:

• Nauczycielka pokazuje, gdzie wstawić przecinek, a gdzie kropkę.

This is also natural and means essentially the same thing.

But repeating the verb:

• gdzie wstawić przecinek, a gdzie postawić kropkę

makes the structure very clear and nicely balanced. It can sound a bit more careful or explicit.

Yes. Polish word order is more flexible than English, though the original version is the most neutral.

Neutral order:

• Nauczycielka pokazuje, gdzie wstawić przecinek, a gdzie postawić kropkę.

A different order for emphasis might be:

• Gdzie wstawić przecinek, a gdzie postawić kropkę, pokazuje nauczycielka.

That version puts extra focus on where the punctuation goes. It is grammatical, but less neutral.

So the original sentence is probably the best basic model for a learner.

Not always. Kropka literally means dot.

Depending on context, it can mean:

• period / full stop in punctuation
• dot as a small round mark

In this sentence, because it appears next to przecinek (comma) and in a punctuation context, it clearly means period (or full stop in British English).

So:

• przecinek = comma
• kropka = period / full stop