Danas sam srećna.

Sam is the 1st person singular present tense of the verb biti (to be), so it means am.

In Danas sam srećna, the structure is:

• Danas = today
• sam = am
• srećna = happy

So this sentence literally follows the pattern Today am happy, which in natural English is I am happy today or Today I am happy.

Serbian often leaves out the subject pronoun ja (I) because the verb form sam already shows who the subject is.

In Serbian, subject pronouns are often omitted when they are clear from the verb.

Here, sam already tells you the subject is I, so ja is not necessary.

You could say:

• Ja sam srećna. = I am happy.

But in many situations, Serbian prefers the shorter version:

• Sam srećna.
• Danas sam srećna.

Adding ja can give emphasis, like I am happy today.

Because Serbian adjectives change form to match the gender of the person they describe.

• srećan = masculine singular
• srećna = feminine singular
• srećno = neuter singular

So:

• a man would say Danas sam srećan.
• a woman would say Danas sam srećna.

This is very common in Serbian: adjectives agree with the noun or person in gender and number.

Yes. Serbian word order is more flexible than English word order.

All of these are possible:

• Danas sam srećna.
• Ja sam danas srećna.
• Srećna sam danas.

They all mean roughly the same thing, but the focus changes a little.

• Danas sam srećna. puts emphasis on today
• Ja sam danas srećna. can emphasize I
• Srećna sam danas. puts emphasis on happy

However, sam is a clitic, which means it usually likes to appear in the second position of the sentence or clause. That is why Danas sam srećna sounds very natural.

Danas means today.

It is an adverb of time, telling you when the speaker is happy.

So in this sentence it modifies the whole statement:

• Danas sam srećna. = Today I am happy.

It does not change form here. It is simply a time word placed at the beginning for emphasis or natural flow.

A helpful approximate pronunciation is:

SRECH-na

More carefully:

• sr at the start can be hard for English speakers because Serbian allows consonant clusters without a vowel in between
• e is like e in met
• ć is a soft sound, somewhat like a very soft ch or ty
• na is pronounced clearly

The letter ć is important. It is softer than č.

So:

• ć = softer
• č = harder, more like English ch

If you are a beginner, SRECH-na is a reasonable starting approximation.

It can do both, depending on context.

In Danas sam srećna, the presence of danas makes it clearly about a temporary state: today I am happy.

But srećna can also describe a person more generally:

• Ona je srećna osoba. = She is a happy person.

So the adjective itself does not have to mean only temporary or only permanent happiness. The context tells you which meaning is intended.

The dictionary form is usually the masculine singular form:

• srećan = happy

From that, you get:

• srećan = masculine
• srećna = feminine
• srećno = neuter

So if you look the word up in a dictionary, you will usually find srećan, even though the sentence uses srećna.

Yes. This sentence pattern is very common:

• Danas sam umorna. = Today I am tired.
• Danas sam gladna. = Today I am hungry.
• Danas sam nervozna. = Today I am nervous.

If the speaker is male, these would usually become:

• umoran
• gladan
• nervozan

So Danas sam + adjective is a very useful pattern for describing how you feel.