Bolesna sam i odmaram se.

Because bolesna is the feminine singular form of bolestan (sick / ill).

So this sentence is said by a female speaker:

• Ja sam bolesna. = I am sick. (female speaker)

A male speaker would say:

• Ja sam bolestan. = I am sick. (male speaker)

This is a very common feature in Serbian: adjectives change to match the gender and number of the person or thing they describe.

Sam is the 1st person singular form of the verb biti (to be) in the present tense.

So:

• sam = I am

In this sentence:

• Bolesna sam literally means Sick am, but in natural English it is I am sick.

Serbian often uses this pattern:

• adjective + form of to be

Examples:

• Umorna sam. = I am tired. (female speaker)
• Srećan sam. = I am happy. (male speaker)

It is understood from the verb form, so Serbian often leaves it out.

• sam already tells you the subject is I
• odmaram also tells you the subject is I

So:

• Bolesna sam i odmaram se. already clearly means I am sick and I am resting.

You could add ja for emphasis:

• Ja sam bolesna i odmaram se.

But normally, Serbian does not need the subject pronoun unless you want contrast, emphasis, or clarity.

In Serbian, Bolesna sam is the normal and natural order.

With short forms like sam, si, je, Serbian has special placement rules. These short unstressed forms usually do not stand at the very beginning of a clause. That is why Sam bolesna sounds wrong in standard usage.

So the natural version is:

• Bolesna sam.

Serbian word order is flexible in many cases, but these little short words often have stricter placement rules.

I means and.

So:

• Bolesna sam i odmaram se. = I am sick and I am resting.

It simply connects the two parts of the sentence:

1. Bolesna sam
2. odmaram se

Because odmarati se is the usual Serbian verb meaning to rest.

The se is a reflexive particle. In many Serbian verbs, it is just part of how the verb is normally used, even when English does not use oneself.

So:

• odmarati se = to rest
• odmaram se = I am resting / I rest

You should learn this as a whole unit:

• odmarati se

Similar verbs:

• smejati se = to laugh
• nadati se = to hope
• bojati se = to be afraid

So the se is not optional here in normal usage.

It can mean either one, depending on context.

The Serbian present tense often covers both:

• I rest
• I am resting

So:

• Odmaram se. can mean:
• I rest
• I am resting
• I’m taking it easy
• I’m resting

In this sentence, because of the situation, the most natural English meaning is usually I am resting.

Because bolesna comes from bolestan, which means ill / sick.

Even though the words may look related to bol (pain), bolestan / bolesna is the normal adjective for being sick.

By contrast:

• bolan / bolna means painful or sore, depending on context

So:

• Bolesna sam. = I am sick.
• Ruka mi je bolna. = My arm hurts / My arm is painful.

It is specifically feminine because of bolesna.

The other forms do not show the speaker’s gender here:

• sam = I am
• odmaram se = I am resting

Only the adjective changes for gender:

• bolesna sam = female speaker
• bolestan sam = male speaker

So if you hear just odmaram se, you cannot tell whether the speaker is male or female. But bolesna gives that information.

Normally, no. The natural verb is odmarati se.

So the correct form is:

• odmaram se

Without se, the sentence sounds incomplete or unnatural in this meaning.

A good rule for learners is: memorize certain Serbian verbs together with se if they normally require it.

Yes, it is completely natural.

It sounds like something someone might say in everyday life when explaining why they are not doing much, not going out, or not coming to work or school.

For example:

• Ne mogu danas napolje. Bolesna sam i odmaram se. = I can’t go out today. I’m sick and resting.

So this is a normal, useful sentence for conversation.

Word-for-word, something like that shows the structure, but it is not how you should translate it naturally into English.

A rough literal breakdown is:

• Bolesna = sick
• sam = am
• i = and
• odmaram se = rest myself / am resting

But natural English is:

• I am sick and I am resting. or simply
• I’m sick and resting.

Literal breakdowns can help you see the grammar, but the real translation should sound natural in English.