Doktorica kaže da mi je krvni tlak danas dobar.

Doktorica is the feminine form, meaning female doctor. Croatian often marks the gender of professions:

• doktor = male doctor
• doktorica = female doctor

So this sentence specifically tells you the doctor is a woman.

Kaže means says. It is the 3rd person singular present tense of the verb kazati or reći in the sense of reporting speech.

So:

• Doktorica kaže = The doctor says

In everyday Croatian, kaže is very common.

Da introduces a subordinate clause, very often corresponding to English that.

So:

• Doktorica kaže da... = The doctor says that...

Just like in English, that can sometimes be omitted in translation, but in Croatian da is normally used here.

Here mi means to me.

It is the dative form of ja (I):

• ja = I
• meni / mi = to me

So da mi je krvni tlak danas dobar literally means something like:

• that to me the blood pressure is good today

In natural English, of course, you would say:

• that my blood pressure is good today

Croatian often uses this dative structure where English uses my.

Croatian has special short unstressed forms called clitics, and they usually come very early in the clause, often in the second position.

Both mi and je are clitics here:

• mi = to me
• je = is

So da mi je krvni tlak danas dobar follows a very normal Croatian clitic order.

Learners often want to say something more like English word order, but Croatian strongly prefers this compact clitic placement.

Je is the 3rd person singular present form of biti (to be), but in its short unstressed form.

So:

• je = is

In this sentence:

• krvni tlak ... je dobar = blood pressure ... is good

Because Croatian clitics move forward, you see je earlier than an English speaker might expect.

Literally:

• krvni = blood-related / blood
• tlak = pressure

So krvni tlak means blood pressure.

This is a fixed medical expression, and it is very common. You may also hear:

• visoki krvni tlak = high blood pressure
• niski krvni tlak = low blood pressure

Dobar means good, and it agrees with krvni tlak.

Since tlak is:

• masculine
• singular

the adjective must also be:

• masculine singular → dobar

Compare:

• tlak je dobar = the pressure is good
• temperatura je dobra = the temperature is good
• srca su zdrava = the hearts are healthy

So the adjective changes depending on the noun it describes.

Danas means today. Its position is flexible, but the sentence sounds natural as given:

• Doktorica kaže da mi je krvni tlak danas dobar.

You could also hear:

• Doktorica kaže da mi je danas krvni tlak dobar.

Both are grammatical. The difference is mostly about emphasis and rhythm, not basic meaning.

Croatian word order is more flexible than English, but not random.

Croatian often avoids using a possessive adjective like moj when ownership is already clear from context.

So instead of:

• moj krvni tlak je dobar = my blood pressure is good

Croatian very naturally says:

• mi je krvni tlak dobar = literally, to me the blood pressure is good

This sounds more natural in many situations. Using moj is possible, but it can sound more explicit or emphatic than necessary.

Yes, the subject is krvni tlak.

In the clause:

• da mi je krvni tlak danas dobar

the thing that is good is krvni tlak.

So the structure is:

• mi = to me
• je = is
• krvni tlak = blood pressure
• danas = today
• dobar = good

Even though the order is not the same as English, krvni tlak is still the grammatical subject.

Not naturally in this sentence.

• kaže = says
• govori = speaks / is speaking / talks

When reporting what someone says, Croatian usually prefers kaže or rekao/rekla je.

So:

• Doktorica kaže da... = natural
• Doktorica govori da... = usually not the best choice here

If you want the doctor is talking about..., then govori can work in other structures.

Not very well. A word-for-word version would be something like:

• The female doctor says that to me is blood pressure today good.

That is not natural English, but it helps show the Croatian structure.

A natural English translation is:

• The doctor says my blood pressure is good today.
• or The doctor says that my blood pressure is good today.

This is a good example of why Croatian and English often express possession and word order differently.