Juče sam napravila plan.

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

It is formed with:

• the present-tense auxiliary biti (sam = I am / I have, as an auxiliary here)
• plus the past participle: napravila

So:

• sam napravila = I made / I have made

In everyday Serbian, this is the normal way to talk about completed actions in the past.

Sam is the 1st person singular auxiliary form of biti used in the past tense.

For I:

• ja sam napravila = I made

In Serbian, the subject pronoun ja is often omitted because sam already shows the person:

• Juče sam napravila plan. = Yesterday I made a plan.

So sam is not optional in standard Serbian past tense; it is an important part of the verb form.

Because the speaker is female.

In Serbian past tense, the participle agrees with the gender of the subject:

• napravila = used by a female speaker
• napravio = used by a male speaker

So:

• Juče sam napravila plan. = said by a woman
• Juče sam napravio plan. = said by a man

This is a very important feature of Serbian and other South Slavic languages.

The verb is napraviti, which means to make, to create, or to do and finish something.

The form napravila is the past participle from napraviti.

A useful comparison:

• praviti = to make, to be making, to work on making
• napraviti = to make, to finish making, to produce a completed result

In this sentence, napraviti is used because the plan was completed.

This is about aspect, which is very important in Serbian.

• praviti is imperfective: focuses on the process, repetition, or ongoing action
• napraviti is perfective: focuses on a completed action

Since the sentence describes a finished action in the past, napraviti is natural:

• Juče sam napravila plan. = yesterday I completed the plan / made the plan

If you used pravila, it would suggest something more like:

• I was making a plan
• I used to make plans
• I was in the process of making a plan

So the perfective verb fits better here.

Juče means yesterday, and putting it first is very natural because it sets the time right away.

Serbian word order is fairly flexible, so you can move elements around for emphasis. But:

• Juče sam napravila plan. is a very normal, neutral sentence.

Starting with Juče highlights when the action happened.

This is one of the most important Serbian word-order rules.

Short unstressed words like sam are clitics, and clitics usually go in second position in the sentence or clause.

So in:

• Juče sam napravila plan.

the first element is Juče, and the clitic sam comes right after it.

That is why you do not normally say:

• Juče napravila sam plan. in neutral standard word order

You will often see Serbian past-tense sentences arranged so that the clitic comes very early:

• Ja sam napravila plan.
• Juče sam napravila plan.
• Plan sam napravila juče.

Serbian does not have articles like English a and the.

So:

• plan can mean a plan or the plan

The exact meaning depends on context.

In this sentence, English often translates it as a plan, but Serbian itself does not mark that with a separate article.

It is in the accusative case because it is the direct object of the verb napravila.

However, plan is a masculine inanimate noun, and many masculine inanimate nouns have the same form in the nominative and accusative singular.

So:

• nominative: plan
• accusative: plan

That is why it looks unchanged.

Compare that with a masculine animate noun, where accusative is often different:

• vidim čoveka = I see the man

But:

• napravila sam plan = I made a plan

Yes. That is also correct.

Serbian allows different word orders depending on emphasis:

• Juče sam napravila plan. = neutral, with time first
• Ja sam juče napravila plan. = adds emphasis to I
• Plan sam napravila juče. = emphasizes plan

The main thing to watch is the clitic sam, which still wants to stay near the beginning, in second position.

It is completely normal to leave it out.

Serbian often omits subject pronouns because the verb phrase already tells you the person:

• sam tells you it is I
• napravila tells you the speaker is feminine

So:

• Juče sam napravila plan. is perfectly natural
• Ja sam juče napravila plan. is also correct, but ja adds emphasis or contrast

For example:

• Ja sam juče napravila plan, a on nije. = I made a plan yesterday, but he didn’t.

A man would say:

• Juče sam napravio plan.

The only change is:

• napravila → napravio

That is because the past participle must agree with the speaker’s gender.

Juče is pronounced approximately like YOO-cheh, but with Serbian sounds:

• j sounds like English y
• u is like oo in food
• č is like ch in church
• e is like e in met or a short clear eh

So:

• Juče ≈ YOO-cheh

Also note that č is a real consonant distinction in Serbian, so it is worth pronouncing it clearly.