Babcia włożyła żółte tulipany do wysokiego wazonu obok okna.

Because in Polish, common nouns are normally not capitalized. babcia means grandma / grandmother as a regular noun, so it stays lowercase in an ordinary sentence.

You would use a capital letter mainly when it works like a name or direct address, for example:

• Babciu, chodź tutaj! = Grandma, come here!

In neutral narration, babcia is lowercase.

In the Polish past tense, the verb agrees with the subject in gender and number.

Here the subject is babcia, which is singular feminine, so the verb is:

• włożyła = she put / grandma put

Compare:

• włożył = he put
• włożyła = she put
• włożyli = they put (masculine-personal group)
• włożyły = they put (non-masculine-personal group)

So the -ła tells you the subject is feminine singular.

This is an aspect question.

• włożyła is perfective: it presents the action as completed.
• wkładała is imperfective: it presents the action as ongoing, repeated, or not viewed as completed.

So:

• Babcia włożyła żółte tulipany... = Grandma put the yellow tulips... / Grandma placed them in...
• Babcia wkładała żółte tulipany... = Grandma was putting the yellow tulips... / used to put...

English often just says put, but Polish usually makes you choose whether the action is completed or not.

Because the adjective has to agree with the noun in number, gender/class, and case.

Here:

• tulipany = plural
• it is the direct object
• tulipan is a masculine inanimate noun, and in the plural it belongs to the non-masculine-personal pattern

For this kind of noun, the accusative plural looks the same as the nominative plural:

• tulipany

The adjective matches that:

• żółte tulipany

So:

• żółte = correct plural form here
• żółty would be singular masculine, so it would not match
• żółtych tulipanów is a different case pattern, not the one needed here

Sometimes yes, but not always.

In Polish, direct objects are usually in the accusative case. However, for many non-masculine-personal plural nouns, the accusative plural is identical to the nominative plural.

So:

• nominative plural: tulipany
• accusative plural: tulipany

That is why the object does not visibly change here.

This is very common with things and animals in some patterns, but with masculine-personal nouns you would often see a clearer difference.

Because the preposition do requires the genitive case.

The basic form is:

• wysoki wazon = a tall vase

After do, it changes to:

• do wysokiego wazonu

So:

• wysoki → wysokiego
• wazon → wazonu

This whole phrase means into the tall vase.

Because obok normally also takes the genitive case.

The basic noun is:

• okno = window

After obok, it becomes:

• okna

So:

• obok okna = next to the window / beside the window

This is a very common pattern:

• obok domu = next to the house
• obok stołu = next to the table

The most natural reading is that it describes the vase:

• do wysokiego wazonu obok okna
• into the tall vase next to the window

In other words, the vase is next to the window.

Why? Because in Polish, a phrase like obok okna usually attaches most naturally to the nearest noun phrase, and here that is wazonu. Context could sometimes make a different interpretation possible, but this sentence strongly suggests the vase is by the window.

Yes. Polish word order is much more flexible than English word order because the case endings help show who is doing what.

The given sentence is a very normal, neutral order:

• Babcia włożyła żółte tulipany do wysokiego wazonu obok okna.

But you can move parts around for emphasis, for example:

• Żółte tulipany babcia włożyła do wysokiego wazonu obok okna.
  • This puts extra focus on yellow tulips.

So word order in Polish often affects emphasis, focus, or style, more than basic grammar.

Because Polish has no articles.

So Polish does not normally have separate words matching English a/an and the. Whether something is definite or indefinite is understood from context.

That means:

• babcia can mean grandma, the grandmother, or sometimes just grandmother
• wazonu can mean a vase or the vase, depending on context

This is completely normal in Polish.

Because the sentence describes movement into the vase.

• do wazonu = into the vase
• w wazonie = in the vase
• na wazon would not work here; na usually suggests movement onto a surface, not into a container

With włożyć in this kind of sentence, do wazonu is the natural choice:

• włożyć kwiaty do wazonu = put flowers into a vase

So the idea is:

• destination into a container → do + genitive