Kad sam s tobom, osjećam se kao kod kuće.

Both kad and kada mean when.

• kad is shorter and very common in everyday speech
• kada is a bit fuller and can sound slightly more formal, careful, or emphatic

So:

• Kad sam s tobom...
• Kada sam s tobom...

Both are correct. In this sentence, kad sounds natural and conversational.

In Croatian, subject pronouns are often omitted when they are already clear from the verb form.

Here, sam means I am, so the I is already understood. Because of that, ja is not necessary.

• Kad sam s tobom... = When I am with you...
• Kad ja sam s tobom... is not correct word order
• Kad sam ja s tobom... is possible, but it adds emphasis, like when I’m with you as opposed to someone else

So the basic, natural version is simply Kad sam s tobom...

After the preposition s meaning with, Croatian normally uses the instrumental case.

The pronoun ti changes like this:

• nominative: ti = you
• instrumental: tobom = with you

So:

• s tobom = with you

This is a very common pattern:

• s njim = with him
• s njom = with her
• s nama = with us
• s vama = with you all / with you formal
• s njima = with them

Yes, you may hear sa tobom, but s tobom is the usual standard form in this sentence.

Croatian has both s and sa for with. Sa is often used to make pronunciation easier, especially before certain consonant clusters. But with tobom, s tobom is the normal choice.

So:

• s tobom = standard and natural here
• sa tobom = understandable, and you may hear it, but it is less typical in standard Croatian for this phrase

If you want the safest version for learning, use s tobom.

Because Kad sam s tobom is a subordinate clause that comes before the main clause.

The sentence structure is:

• Kad sam s tobom = subordinate clause
• osjećam se kao kod kuće = main clause

In Croatian, when a clause beginning with kad comes first, it is normally followed by a comma.

So the comma works much like in English:

• When I’m with you, I feel at home.

Because osjećati se is the reflexive verb used for to feel in the sense of to feel a certain way.

• osjećam se dobro = I feel good
• osjećam se loše = I feel bad
• osjećam se kao kod kuće = I feel at home

Without se, osjećati usually means to feel/sense something as a direct object:

• Osjećam bol. = I feel pain.
• Osjećam hladnoću. = I feel coldness.

So:

• osjećam se = I feel, I feel myself, I feel in a certain state
• osjećam = I feel something

In this sentence, the reflexive form is required.

Literally:

• kao = like / as
• kod kuće = at home

So osjećam se kao kod kuće means something like I feel as if I were at home or more naturally I feel at home.

A useful detail: Croatian often uses kao kod kuće where English would simply say at home.

It gives the idea of comfort, safety, and familiarity.

Because kod is a preposition, and it requires a particular case. After kod, nouns go in the genitive.

The noun is:

• nominative: kuća = house / home
• genitive: kuće

So:

• kod kuće = at home

This is a fixed, very common expression in Croatian. Even though kod often literally means something like at someone’s place or by, in kod kuće it simply means at home.

Yes. The preposition kod takes the genitive case.

That is why kuća changes to kuće.

You can see the same pattern in other examples:

• kod prijatelja = at a friend’s place
• kod liječnika = at the doctor’s
• kod bake = at grandma’s
• kod kuće = at home

So the form kuće is not random. It is there because kod requires it.

Yes, in many contexts you can say Osjećam se doma, and it also means I feel at home.

However, there is a slight difference in style and nuance:

• osjećam se kao kod kuće = I feel as if I’m at home; very idiomatic, warm, expressive
• osjećam se doma = I feel at home; shorter and also natural

The version in your sentence is especially good if you want to emphasize the comparison: being with that person makes you feel as comfortable as you do at home.

The given word order is the most neutral and natural:

• Kad sam s tobom, osjećam se kao kod kuće.

Croatian word order is somewhat flexible, but not every change sounds equally natural.

For example:

• Osjećam se kao kod kuće kad sam s tobom.
  Also correct. This puts the main statement first and the when clause second.

Within the first clause, Kad sam s tobom is the normal order. Croatian clitic placement and verb placement can make some rearrangements sound awkward, so for a learner, it is best to keep this sentence as it is.

A rough pronunciation guide:

• osjećam ≈ oh-SYE-cham
• kuće ≈ KOO-cheh

A few important sounds:

• ć is a soft ch-like sound
• č and ć are different in Croatian, though many learners find them hard at first
• j is pronounced like English y
• je in osjećam is pronounced together, roughly like ye

You do not need perfect pronunciation immediately, but it helps to notice that both osjećam and kuće contain ć, not č.