Când am ajuns la curs, Ana plecase deja, dar îmi lăsase o scurtă traducere pe masă.

Because Romanian is showing two different layers of past time.

• am ajuns = perfectul compus
  This is the normal conversational past: I arrived.

• plecase and lăsase = mai mult ca perfectul
  This is the pluperfect: had left and had left behind.

So the timeline is:

1. Ana had already left
2. Ana had left me a short translation
3. later, I arrived

That is why Romanian uses:

• Când am ajuns... = When I arrived...
• Ana plecase deja... = Ana had already left...
• îmi lăsase... = had left me...

This is one of the most important things happening in the sentence.

Plecase is the 3rd person singular form of the mai mult ca perfectul of a pleca (to leave, to go away).

So:

• a pleca = to leave
• plecase = he/she had left

In this sentence:

• Ana plecase = Ana had left

This tense is formed from the verb stem plus a special ending. It is a single-word tense, unlike English had left, which uses two words.

Lăsase is also mai mult ca perfectul, from a lăsa (to leave, to leave behind, to put down depending on context).

So:

• a lăsa = to leave
• lăsase = had left

In this sentence:

• îmi lăsase o scurtă traducere pe masă = had left me a short translation on the table

Just like plecase, it shows an action completed before the moment of arrival.

Romanian often drops subject pronouns because the verb ending usually makes the subject clear.

• am ajuns already tells you the subject is I
• so eu is unnecessary unless you want emphasis

Compare:

• Când am ajuns... = normal, neutral
• Când eu am ajuns... = more emphatic, often unnecessary here

Romanian does this much more than English.

Când means when.

It introduces a time clause:

• Când am ajuns la curs = When I arrived at class

It is very common in Romanian for talking about the moment something happened.

Examples:

• Când am venit, el dormea. = When I came, he was sleeping.
• Când am intrat, ea plecase deja. = When I entered, she had already left.

La curs means to class / at class / to the lesson, depending on context.

Here, with am ajuns la curs, it means something like:

• I arrived at class
• I got to class

The preposition la is very common with places/events you arrive at:

• a ajunge la școală = to arrive at school
• a ajunge la birou = to arrive at the office
• a ajunge la curs = to arrive at class

Romanian often uses la where English might use at or to.

Both are possible, but they mean slightly different things.

• la curs = to class / to the lesson, more general and natural in many contexts
• la cursul = to the course / to the specific lesson, more definite and specific

In everyday Romanian, la curs is very normal when talking about going to class in general.

So:

• Am ajuns la curs = I arrived at class
• Am ajuns la cursul de română = I arrived at the Romanian class/course

Deja means already.

So:

• Ana plecase deja = Ana had already left

It emphasizes that Ana’s leaving happened before the speaker arrived, and that this was already the case by that time.

Romanian uses deja very much like English already.

That is a very natural Romanian word order.

• Ana plecase deja = neutral, standard
• Ana deja plecase is also possible, but it can sound a bit more marked depending on context

Romanian word order is fairly flexible, but the version in your sentence is probably the most natural one for everyday speech.

Dar means but.

It connects two ideas:

• Ana had already left
• but she had left a short translation on the table

So it shows a contrast:

• she was gone,
• yet she had still done something helpful.

Îmi means to me / for me. It is an indirect object clitic.

In this sentence:

• îmi lăsase = had left me

So:

• Ana îmi lăsase o scurtă traducere
  literally: Ana had left to me a short translation naturally: Ana had left me a short translation

This is very common in Romanian:

• îmi spune = tells me
• îmi dă = gives me
• îmi lasă = leaves me

Because the sentence needs the pluperfect, not the ordinary conversational past.

• mi-a lăsat = left me / has left me depending on context
• îmi lăsase = had left me

Since this action happened before the arrival, Romanian uses lăsase.

So:

• Când am ajuns, Ana mi-a lăsat... would not fit the timeline well
• Când am ajuns, Ana îmi lăsase... correctly means she had done it earlier

Also, îmi and mi- are just different phonetic shapes of the same pronoun:

• îmi lăsase
• mi-a lăsat

They are two forms of the same pronoun, chosen by sound and grammar.

• îmi is used before many verbs in simple forms:

  • îmi spune
  • îmi lasă
  • îmi lăsase

• mi- often appears before another word starting with a vowel, especially in combinations:

  • mi-a spus
  • mi-a lăsat

So here:

• îmi lăsase is the correct natural form

O here is the feminine singular indefinite article, meaning a/an.

Because:

• traducere is a feminine noun
• so its indefinite article is o

Compare:

• un curs = a class/course (masculine/neuter singular)
• o traducere = a translation (feminine singular)

So:

• o scurtă traducere = a short translation

Because adjectives in Romanian must agree with the noun in gender and number.

• traducere is feminine singular
• so the adjective must also be feminine singular
• therefore: scurtă

Compare:

• un text scurt = a short text
• o traducere scurtă = a short translation

In your sentence, the adjective is placed before the noun:

• o scurtă traducere

That is perfectly correct and often sounds a bit more literary or stylistically neat than o traducere scurtă.

Yes.

Both are possible:

• o scurtă traducere
• o traducere scurtă

The difference is mostly one of style and emphasis, not basic meaning.

Very roughly:

• o scurtă traducere can sound a bit more elegant or descriptive
• o traducere scurtă is also very normal and often feels a bit more neutral

Romanian allows much more adjective placement flexibility than English in some cases.

Here it means short/brief in terms of length or size of the text, not physical height or distance.

So:

• o scurtă traducere = a short translation
• meaning probably a brief translation, not a long one

Romanian scurt can be used both literally and figuratively, just like English short.

Romanian expresses this idea very compactly.

• îmi lăsase o scurtă traducere already means had left me a short translation
• no extra pronoun is needed because o scurtă traducere is the direct object already stated

If Romanian wanted to replace the noun with a pronoun, then it would use clitics:

• Mi-o lăsase pe masă. = She had left it for me on the table.

But since the noun is fully present, the sentence simply says:

• îmi lăsase o scurtă traducere

Pe masă means on the table.

• pe = on
• masă = table

So:

• a lăsa ceva pe masă = to leave something on the table

This is a basic prepositional phrase showing location.

It is the same word, but not the same function.

Romanian pe can be:

1. a normal preposition:

   • pe masă = on the table
   • pe stradă = on the street

2. a marker used with certain direct objects, especially people:

   • o văd pe Ana = I see Ana

In your sentence, pe masă is just the ordinary preposition on.

Romanian often leaves the noun without the article in some location phrases when the context is enough.

• pe masă = on the table
• pe masa would not be correct by itself here
• pe masă is the standard phrase

If you wanted to say on the table in a more specifically definite way, you would usually say:

• pe masă in many ordinary contexts anyway, or
• pe masa din sală = on the table in the room

Romanian does not always match English article use one-for-one.

This order is natural because it presents the events in a clear logical way:

1. first important fact: Ana had already left
2. contrasting second fact: but she had left me something

So the sentence first tells you she was gone, then adds the useful detail.

Romanian could rearrange things for emphasis, but this version is straightforward and elegant.

Because both actions happened before the arrival.

The arrival is the main reference point:

• Când am ajuns... = when I arrived

Relative to that moment:

• Ana had left
• Ana had left a translation

So both are earlier-than-earlier events, which is exactly what the pluperfect is for.

Yes, that is possible.

• Ana plecase deja = very natural, neutral
• Ana deja plecase = also possible, with a slightly different rhythm or emphasis

The original version is probably the most standard and idiomatic in neutral narration.

Because it is not necessary. The subject is understood from context.

• Ana plecase deja, dar îmi lăsase... naturally means:
  • Ana had already left, but (she) had left me...

Romanian often omits repeated subjects when they are clear.

You could say:

• Ana plecase deja, dar Ana îmi lăsase... but that would sound repetitive.

Usually traducere means translation, especially a written translation.

For interpreting (spoken translation), Romanian often uses:

• interpretare
• or phrases like traducere orală, depending on context

So in this sentence, o scurtă traducere most naturally suggests:

• a short written translation
• perhaps a note, version, or translated passage

Yes: it shows a very common Romanian pattern for narrating past events with clear time relationships.

Romanian often uses:

• perfectul compus for the main past event
• mai mult ca perfectul for earlier events

So a useful model is:

• Când am ajuns, el plecase deja.
• Când am intrat, ea terminase.
• Când am deschis ușa, cineva îmi lăsase un mesaj.

This is a strong pattern to learn, because it helps you talk naturally about what had already happened before something else in the past.