Nemoj zaboraviti jutarnju dozu, čak i ako se danas osjećaš bolje.

Because nemoj zaboraviti is the normal way to make a negative command to one person in Croatian.

• nemoj zaboraviti = don’t forget
• literally, nemoj comes from moći in a special imperative-like form used for negative commands

This is much more natural than trying to negate a positive imperative directly. For singular informal you, the pattern is:

• Nemoj + infinitive

For plural or formal you, it becomes:

• Nemojte + infinitive

So:

• Nemoj zaboraviti = don’t forget
• Nemojte zaboraviti = don’t forget (to several people / formal)

This is about verb aspect, which is very important in Croatian.

• zaboraviti = perfective
• zaboravljati = imperfective

Here, the speaker is talking about one specific complete action: not forgetting the morning dose. That is why zaboraviti is the natural choice.

So:

• Nemoj zaboraviti = don’t forget it
• Nemoj zaboravljati would sound more like don’t keep forgetting or don’t be in the habit of forgetting

In this sentence, the perfective verb fits best because the focus is on a single act of remembering to take the dose.

Because this is the direct object of the verb zaboraviti, so it must be in the accusative case.

The base form is:

• jutarnja doza = morning dose

But after zaboraviti:

• zaboraviti jutarnju dozu

Both words change because the noun phrase is feminine singular accusative:

• jutarnja → jutarnju
• doza → dozu

This is a very common pattern with feminine nouns ending in -a.

Čak i ako means even if.

It adds emphasis compared with plain ako.

• ako = if
• čak i ako = even if

So the sentence is stronger than just saying if you feel better today. It means that feeling better does not change the instruction.

You may also see:

• i ako in some contexts, but čak i ako is the clearest equivalent of even if

The verb is osjećati se, which means to feel in the sense of physical or emotional condition.

So:

• osjećati by itself is more like to perceive / to feel something
• osjećati se = to feel, as in to feel well, sick, better, tired

Examples:

• Osjećam se dobro. = I feel good.
• Osjećaš se loše. = You feel bad.

In your sentence:

• osjećaš se = you feel

The little word se is part of the verb and should be learned together with it.

Osjećaš is the 2nd person singular present tense form, so the speaker is talking to one person informally.

That matches nemoj, which is also singular informal.

So the sentence is addressed to:

• one person
• in a familiar or informal way

If you wanted the formal or plural version, you would say:

• Nemojte zaboraviti jutarnju dozu, čak i ako se danas osjećate bolje.

Compare:

• osjećaš se = you feel, singular informal
• osjećate se = you feel, plural or formal

Because bolje is being used adverbially/predicatively after osjećati se.

With osjećati se, Croatian commonly uses forms like:

• dobro = well
• loše = badly / unwell
• bolje = better
• gore = worse

So:

• osjećati se bolje = to feel better

You do not normally match it to the gender of the person here. You just use bolje as the natural expression.

Croatian word order is fairly flexible, so danas can move, although some versions sound more natural than others.

Your sentence:

• čak i ako se danas osjećaš bolje

Possible alternatives:

• čak i ako se osjećaš bolje danas
• čak i ako se bolje osjećaš danas

These are grammatically possible, but the original sounds very natural and neutral. Putting danas before osjećaš bolje nicely emphasizes today.

So yes, the word order can change, but the original version is a very standard choice.

Because čak i ako se danas osjećaš bolje is a subordinate clause attached to the main instruction.

Main clause:

• Nemoj zaboraviti jutarnju dozu

Subordinate clause:

• čak i ako se danas osjećaš bolje

Croatian often uses a comma before this kind of clause, especially when it comes after the main clause. So the punctuation here is normal and expected.

Yes. Doza is a very normal word for dose, especially in medical or health-related contexts.

So jutarnja doza naturally means:

• morning dose
• the dose you take in the morning

Depending on context, Croatian could also use expressions like:

• jutarnji lijek = morning medicine
• jutarnja tableta = morning pill

But jutarnja doza is perfectly natural when the important idea is the prescribed amount.

You would change both the negative command and the verb form.

Informal singular:

• Nemoj zaboraviti jutarnju dozu, čak i ako se danas osjećaš bolje.

Formal or plural:

• Nemojte zaboraviti jutarnju dozu, čak i ako se danas osjećate bolje.

Changes:

• nemoj → nemojte
• osjećaš se → osjećate se

Everything else stays the same.

This is a word learners often stumble over because of the cluster sj and the letter ć.

A rough guide:

• o-sje-ćaš

Helpful pronunciation notes:

• sj is pronounced smoothly together, not as a hard English s plus j
• ć is a softer sound than č
• š sounds like English sh

A rough English-style approximation would be something like os-ye-chash, but that is only approximate.

It helps to hear and repeat these related forms:

• osjećam se
• osjećaš se
• osjeća
• osjećate se

That makes the pattern easier to internalize.