Dzieci zachowują się ciszej, a on zachował się bardzo grzecznie, kiedy starsza pani poprosiła go o miejsce w autobusie.

They come from the same verb pair:

• zachowywać się = imperfective
• zachować się = perfective

In this sentence:

• Dzieci zachowują się ciszej uses the imperfective present: it describes an ongoing or general way of behaving.
• on zachował się bardzo grzecznie uses the perfective past: it refers to one completed act of behavior in that specific situation.

So Polish is showing two different viewpoints:

• ongoing / general behavior → imperfective
• one completed instance → perfective

Here się is part of the verb zachowywać się / zachować się, which means to behave.

So:

• zachowywać by itself can mean to keep / preserve
• zachowywać się means to behave

In other words, you should learn this as a single verb expression, not as a main verb plus a separately translatable się.

A very useful habit is to memorize it as:

• zachowywać się = to behave
• zachować się = to behave / to conduct oneself (in one finished situation)

Ciszej is the comparative form of the adverb cicho.

• cicho = quietly
• ciszej = more quietly / quieter

So Dzieci zachowują się ciszej means that the children are behaving more quietly than before, than usual, or than someone else.

Polish often uses a comparative even when the second half of the comparison is not stated explicitly. English can do this too:

• The children are quieter.

without saying exactly than what.

Because after a verb like zachować się you need an adverb, not an adjective.

• grzeczny = polite / well-behaved (adjective, used for a noun)
• grzecznie = politely / in a well-behaved way (adverb, used for a verb)

Compare:

• On jest grzeczny. = He is polite / well-behaved.
• On zachował się grzecznie. = He behaved politely.

So in your sentence, grzecznie describes how he behaved.

Because starsza pani is the more natural and polite expression for an older/elderly lady.

• starsza pani = older lady, elderly lady, respectful/polite
• stara pani = old lady, which can sound blunt or rude depending on context

Even though starsza is formally the comparative of stary, in many contexts it functions as the normal polite way to refer to an older person.

So this choice is not just grammar; it is also about tone and politeness.

Go is the accusative form of on.

The verb pattern is:

• poprosić kogoś o coś = to ask someone for something

So:

• kogo? → go = him
• o co? → o miejsce = for a seat

That is why the sentence has:

• poprosiła go o miejsce

You may also see the fuller pronoun form jego, but go is more common here when unstressed.

Yes. Literally miejsce means place, but in transport contexts it often means seat.

The verb pattern is:

• prosić / poprosić kogoś o coś = to ask someone for something

After o, this verb takes the accusative:

• o miejsce
• o pomoc
• o radę

In a bus, miejsce is naturally understood as a seat. This is very common in Polish. Compare also:

• ustąpić miejsca = to give up one’s seat

So poprosiła go o miejsce w autobusie means she asked him to give her his seat.

Because w is used here for location, and it takes the locative case.

• autobus → w autobusie

This means in/on the bus. English usually says on the bus, but Polish normally uses w autobusie.

So the pattern is:

• w domu = in the house
• w pokoju = in the room
• w autobusie = on/in the bus

It is a good reminder that prepositions do not match one-to-one between English and Polish.

No. Polish word order is fairly flexible.

This version:

• a on zachował się bardzo grzecznie

is natural and neutral.

You could also hear:

• a on się zachował bardzo grzecznie

Both are possible, but the rhythm and emphasis are slightly different.

A useful thing to remember is that się usually does not stand at the very beginning of a clause, and it often appears near the verb. Beyond that, Polish word order can shift to highlight different parts of the sentence.

Because poprosiła is perfective, and it presents the request as one completed event.

• prosiła = she was asking / she used to ask / she kept asking
• poprosiła = she asked (once, as a completed act)

In this sentence, the older lady makes a single request, and his polite behavior happens in response to that completed event. That makes poprosiła the natural choice.

If you used prosiła, it would suggest a different nuance, such as duration, repetition, or background action.

Because Polish does not have articles like English a/an and the.

So Polish simply says:

• dzieci
• starsza pani
• miejsce
• autobus

Whether something is definite or indefinite is usually understood from:

• context
• word order
• the situation
• sometimes extra words like ten, jakiś, etc.

So learners need to get used to Polish nouns appearing without articles, even when English requires them.

Because dzieci is a plural noun, so the verb must also be plural.

• dziecko = child
• dzieci = children

That is why you get:

• Dzieci zachowują się... = The children behave / are behaving...

Even though dzieci does not end in a typical plural ending like some other nouns, it is a plural form and takes a plural verb.