Na krevetu sjedi mali medvjedić, a pokraj njega leži stara lutka.

Because na can take different cases depending on meaning:

• na + accusative = movement onto something
  
  • Sjeda na krevet. = He/she is sitting down onto the bed.
• na + locative = location on something
  
  • Sjedi na krevetu. = He/she is sitting on the bed.

In your sentence, the teddy bear is already located there, so Croatian uses the locative: na krevetu.

Krevetu is locative singular of krevet (bed).

The basic form is:

• krevet = nominative singular

After na when it means location, Croatian uses the locative, so:

• na krevetu = on the bed

Because pokraj requires the genitive case.

The pronoun on means he, but after pokraj you need its genitive form:

• on = nominative
• njega = genitive/accusative form

So:

• pokraj njega = next to him / beside it

Here njega refers to mali medvjedić.

Grammatically, it comes from the masculine noun medvjedić, so Croatian uses the masculine pronoun njega.

In English, you might translate it as either:

• next to him
• next to it

If the teddy bear is treated like a little character, him feels natural. If it is treated simply as a toy, it is also possible in English. Croatian still uses njega because medvjedić is grammatically masculine.

They describe different positions:

• sjedi = is sitting
• leži = is lying

So:

• mali medvjedić sjedi = the little teddy bear is sitting
• stara lutka leži = the old doll is lying

These are very common Croatian verbs for describing where things or people are positioned.

Because adjectives must agree with the noun in gender, number, and case.

Here both noun phrases are in the nominative singular, but the nouns have different genders:

• medvjedić is masculine
• lutka is feminine

So the adjective changes form:

• mali medvjedić = masculine singular
• stara lutka = feminine singular

This kind of agreement is one of the most important features of Croatian grammar.

Not exactly. Medvjedić is a diminutive form.

• medvjed = bear
• medvjedić = little bear / teddy bear

In this sentence, medvjedić clearly means a teddy bear, not a real bear. Diminutives are very common in Croatian and often make a word sound smaller, cuter, or more affectionate.

In Croatian, a comma is normally used before the conjunction a when it links two clauses in contrast or parallel description.

Here:

• Na krevetu sjedi mali medvjedić, a pokraj njega leži stara lutka.

The sentence presents two connected pieces of information:

• the teddy bear is sitting on the bed
• the old doll is lying next to it

So the comma before a is standard Croatian punctuation.

It often translates as and, but not always exactly.

A usually connects two ideas with a slight sense of contrast, comparison, or scene-setting:

• X..., a Y... = X..., and/while Y...

In this sentence, a introduces another part of the picture:

• A little teddy bear is sitting on the bed, and/while an old doll is lying next to it.

So a is not just a plain list-making and. It often has a softer contrastive feel than English and.

Yes. Croatian word order is more flexible than English because case endings show grammatical roles.

The given sentence is natural and descriptive:

• Na krevetu sjedi mali medvjedić, a pokraj njega leži stara lutka.

But other word orders are possible, for example:

• Mali medvjedić sjedi na krevetu, a stara lutka leži pokraj njega.

This version may sound a bit more neutral to an English speaker because it starts with the subject. The original version emphasizes the location first, which is very common in descriptions.

Because Croatian has no articles.

English says:

• a little teddy bear
• the bed
• an old doll

Croatian simply says:

• mali medvjedić
• krevetu
• stara lutka

Whether something is a, an, or the is understood from context. That is one reason why word order and context are especially important in Croatian.

Because Croatian uses the present tense to describe what is happening in a scene, just like English.

• sjedi = sits / is sitting
• leži = lies / is lying

In this kind of descriptive sentence, English usually prefers is sitting and is lying, while Croatian simply uses the present forms.

No. Croatian has several ways to express this idea, including:

• pokraj = beside / next to
• kraj = by / next to
• pored = next to / beside

All of these are common, though style and regional preference can vary. In your sentence, pokraj njega is perfectly natural and slightly descriptive in tone.