Imala sam sreće.

Because imala is the feminine singular past active participle, so it tells you the speaker is female.

• imao sam = I had (said by a man)
• imala sam = I had (said by a woman)

In Serbian past tense, the participle agrees with the subject in gender and number.

Sam is the 1st person singular form of the auxiliary verb biti (to be) used to form the past tense.

So the structure is:

• imala = main verb participle
• sam = auxiliary am

Together, imala sam means I had.

This is the normal Serbian past-tense pattern:

• radio sam = I worked
• videla sam = I saw
• imala sam = I had

In standard Serbian, the auxiliary sam is a clitic, which means it usually goes in the second position of the sentence or clause.

That is why Imala sam sreće is the natural order here.

You may also see:

• Ja sam imala sreće.

Here sam is still in second position, after ja.

So:

• Imala sam sreće. = natural without an expressed subject
• Ja sam imala sreće. = natural with ja for emphasis or contrast

Because Serbian often omits subject pronouns when they are already clear from the verb form.

In imala sam, the sam already tells you it is I, and imala shows feminine gender.

So ja is not necessary unless you want emphasis:

• Imala sam sreće. = I had luck / I was lucky
• Ja sam imala sreće. = I was lucky

Because after imati in this expression, Serbian commonly uses the genitive case: imati sreće.

• sreća = nominative form, the dictionary form
• sreće = genitive singular

So the expression is literally something like to have luck.

This is a very common fixed phrase:

• Imam sreće. = I am lucky / I have luck
• Imao je sreće. = He was lucky

This is part of an idiomatic Serbian pattern. With some nouns, especially when talking about having a certain amount or kind of something in a general sense, Serbian uses genitive after imati.

With sreća, the natural expression is:

• imati sreće = to be lucky / to have luck

It does not usually mean one specific, countable luck. It is more like possessing the quality or experience of luck.

Yes, but it usually does not sound the same.

• Imala sam sreće = I was lucky
• Imala sam sreću = I had the luck / I had good fortune

The version with genitive (sreće) is the normal idiomatic way to express being lucky.

The accusative sreću is possible in some contexts, but it often sounds more literal, less idiomatic, or context-dependent.

In natural English, I was lucky is usually the best translation.

Literally, Serbian says I had luck, but English normally expresses that idea with be lucky.

So:

• literal: I had luck
• natural English: I was lucky

It is the past tense, specifically the form often called the perfect in Serbian grammar.

It is built with:

1. the past active participle of the main verb
2. the present tense of biti as an auxiliary

So:

• imala = participle of imati
• sam = auxiliary

Together: imala sam = I had

The dictionary form is imati, which means to have.

Some related forms:

• imati = to have
• imam = I have
• imao sam = I had (male speaker)
• imala sam = I had (female speaker)

A male speaker would say:

• Imao sam sreće.

That is the same sentence, but with the masculine participle imao instead of the feminine imala.

Yes, but some versions are more natural than others.

Common possibilities:

• Imala sam sreće.
• Ja sam imala sreće.

The first is neutral and very common. The second adds emphasis to I.

Because sam is a clitic, you generally should not place it freely anywhere you want.

A rough pronunciation is SRE-cheh.

More precisely:

• sr is pronounced together, without a vowel between them
• ć is a soft sound, somewhat like a very soft ch
• e is a short eh

For an English speaker, sreće can be tricky because sr at the start of a syllable is unusual in English.

Yes. It is a completely natural, complete sentence in Serbian.

It already contains:

• the verb
• the subject information
• the object expression

Even without ja, it is fully grammatical and fully understandable.

Use Ja sam imala sreće when you want to emphasize I:

• in contrast with someone else
• to clarify who you mean
• to add emotional emphasis

For example:

• Oni nisu imali sreće, ali ja sam imala sreće. = They were not lucky, but I was.

Without emphasis, Imala sam sreće is usually enough.