Minulla on lempikissa.

Finnish usually does not express possession with a verb meaning to have the way English does. Instead, it uses a structure that is literally closer to at me is.

So:

• minä = I
• minulla = on me / at me
• on = is
• lempikissa = favorite cat

So Minulla on lempikissa is literally something like At me is a favorite cat, but the natural English meaning is I have a favorite cat.

This is a very common question.

• olen = I am
• on = is

In Minulla on lempikissa, the word minulla is not the grammatical subject in the same way English I is. The sentence is built as a possession/existence structure, so Finnish uses on.

Think of it like this:

• Minä olen opettaja = I am a teacher
• Minulla on kissa = I have a cat

So you use olen when I am the subject of being, but on in this possession pattern.

The ending -lla is the adessive case ending. Very roughly, it often has meanings like:

• on
• at
• with

In possession sentences, Finnish uses this case for the possessor:

• minulla = on me / at me
• sinulla = on you / at you
• hänellä = on him/her / at him/her

Examples:

• Minulla on koira = I have a dog
• Sinulla on aikaa = You have time

So here, minulla is the form needed for I have.

Yes, lempikissa is one word because it is a compound noun, which is very common in Finnish.

It is made of:

• lempi- = favorite
• kissa = cat

So lempikissa means favorite cat.

Finnish forms many ideas this way:

• lempiruoka = favorite food
• lempiväri = favorite color
• lempikirja = favorite book

English often uses separate words where Finnish prefers a compound.

Here lempikissa is in the nominative singular, which is the basic dictionary form.

In a positive possession sentence like this, the thing possessed is often in the nominative:

• Minulla on kissa = I have a cat
• Minulla on lempikissa = I have a favorite cat

So there is no extra ending here because the basic form is what the structure calls for.

A useful comparison:

• Minulla on lempikissa = I have a favorite cat
• Minulla ei ole lempikissaa = I do not have a favorite cat

In the negative version, the noun changes form.

Finnish has no articles, so there is no separate word for a, an, or the.

That means:

• kissa can mean a cat or the cat
• lempikissa can mean a favorite cat or sometimes the favorite cat, depending on context

The exact meaning comes from the situation, not from an article.

So in this sentence, English needs a, but Finnish does not.

By itself, lempikissa means favorite cat. It does not automatically mean my favorite cat.

If you want to say my favorite cat as a noun phrase, you would normally say:

• minun lempikissani
  or simply
• lempikissani

Those mean my favorite cat.

But Minulla on lempikissa means I have a favorite cat, which is a full sentence expressing possession, not just a noun phrase.

Not if you want the same meaning.

• Minulla on lempikissa = I have a favorite cat
• Minun lempikissani = my favorite cat

The first is a complete sentence.
The second is just a noun phrase unless you add more words.

For example:

• Minun lempikissani on musta = My favorite cat is black

So these are related ideas, but they are not interchangeable.

The most neutral word order is:

• Minulla on lempikissa

This is the normal way to say it.

Finnish word order is more flexible than English, but changing it usually changes the emphasis. For example:

• Lempikissa on minulla

This sounds marked or contrastive, as if emphasizing that I am the one who has a favorite cat, or that a favorite cat is what I have.

So for a beginner, Minulla on lempikissa is the safe and natural order.

Very useful pattern to learn.

Question:

• Onko minulla lempikissa? = Do I have a favorite cat?

Here -ko turns the clause into a yes/no question.

Negative:

• Minulla ei ole lempikissaa. = I do not have a favorite cat.

Notice two things:

• on changes to ei ole
• lempikissa becomes lempikissaa

That noun change is normal in negative possession/existence sentences.

Yes, it is grammatical and understandable.

It sounds like a normal way to say that you have one cat that is your favorite, or that among cats there is one you especially like. The exact nuance depends on context.

If the context is about pets, preferences, or favorite animals, the sentence works well. The most important thing for a learner is that it shows a very common Finnish pattern:

• Minulla on... = I have...

That is one of the most useful sentence types in Finnish.