També em fa mal l'esquena quan treballo molt.

Because Catalan usually expresses physical pain with the pattern:

[indirect object pronoun] + fer mal + body part

So:

• em = to me
• fa mal = hurts / causes pain
• l'esquena = the back

Literally, it is closer to the back causes pain to me.

This is a very common Catalan structure:

• Em fa mal el cap = My head hurts
• Em fan mal les cames = My legs hurt

Using la meva esquena is not the normal everyday way to say it here.

Em is the unstressed object pronoun meaning to me.

In em fa mal l'esquena, it shows who feels the pain.

Compare:

• Em fa mal l'esquena = My back hurts / My back hurts me
• Et fa mal l'esquena = Your back hurts
• Li fa mal l'esquena = His/her back hurts

So em does not mean my. It means to me.

Catalan usually uses the definite article with body parts when the owner is already clear from the pronoun.

So:

• em fa mal l'esquena literally uses the back
• but in English we usually say my back

This is very normal in Catalan and also happens in other Romance languages.

More examples:

• Em rento les mans = I wash my hands
• Li fa mal el genoll = His/her knee hurts

So the article is not strange in Catalan; it is the expected choice.

Because la becomes l' before a vowel sound.

• la esquena → l'esquena

This is called elision. It makes pronunciation smoother.

Other examples:

• l'amic
• l'àvia
• l'orella

So l'esquena is simply la esquena after normal contraction.

Because the grammatical subject is singular:

• l'esquena = the back → singular

So the verb is singular:

• fa mal = hurts

If the thing that hurts is plural, then the verb becomes plural:

• Em fan mal les espatlles = My shoulders hurt
• Em fan mal els peus = My feet hurt

So the verb agrees with the body part, not with the person feeling the pain.

També means also / too.

At the beginning, it gives the idea of also applying to the whole statement:

• També em fa mal l'esquena... = My back also hurts...

This often suggests that something else was mentioned before, for example another symptom:

• Em fa mal el coll. També em fa mal l'esquena.

Its position is fairly natural at the start, though Catalan word order can sometimes vary for emphasis.

Catalan often omits subject pronouns because the verb ending already shows the person.

• treballo = I work
• the -o ending already tells you it is I

So:

• quan treballo molt = when I work a lot

You can say quan jo treballo molt, but jo is usually added only for emphasis, contrast, or clarity.

Treballo is the 1st person singular present indicative of treballar:

• jo treballo = I work

Full present tense:

• jo treballo
• tu treballes
• ell/ella treballa
• nosaltres treballem
• vosaltres treballeu
• ells/elles treballen

In the sentence, quan treballo molt means when I work a lot or sometimes when I work too much, depending on context.

Here molt is an adverb, meaning a lot / much / very much, modifying the verb treballo.

• treballo molt = I work a lot

You use molt directly after the verb.

Molt de is used before nouns:

• molta feina = a lot of work
• molt de temps = a lot of time

So:

• treballo molt = correct
• treballo molta estona = also possible, but different wording

In this sentence, quan means when.

• quan treballo molt = when I work a lot

Depending on context, it can sometimes feel like whenever, especially in general statements:

• Em fa mal l'esquena quan treballo molt = My back hurts when(ever) I work a lot

So the exact English choice depends on style and context, but when is the basic meaning.

Not with the same meaning.

• quan treballo molt = when I work a lot
• perquè treballo molt = because I work a lot

So:

• Em fa mal l'esquena quan treballo molt = My back hurts when I work a lot
• Em fa mal l'esquena perquè treballo molt = My back hurts because I work a lot

The first talks about time/situation. The second gives a reason.

Usually yes, especially in this sentence.

L'esquena refers to the back of the body, especially the area that commonly hurts from posture, work, or strain.

In many everyday contexts, it matches English back very well:

• Em fa mal l'esquena = My back hurts

If needed, Catalan can be more specific with other words for different areas, but esquena is the normal word here.

A few useful points:

• també has stress on the last syllable because of the accent: tam-BÉ
• em fa mal is usually said smoothly together
• l'esquena begins with the article attached to the noun: les-QUE-na roughly
• treballo in standard Catalan is roughly tre-BA-llo, with the ll being a special Catalan sound

You do not pause between l' and esquena. It is one smooth unit: l'esquena.

Yes, to some extent. Catalan allows some flexibility, but the original sentence is very natural:

També em fa mal l'esquena quan treballo molt.

Possible variations include:

• Em fa mal l'esquena també quan treballo molt.
• Quan treballo molt, també em fa mal l'esquena.

These can slightly change emphasis, but the original is a very normal everyday order.