Porta'm un altre bol, perquè en aquest no hi cap tota l'amanida.

'm is the weak pronoun em, meaning me.

In affirmative commands in Catalan, weak pronouns usually go after the verb, not before it. So:

• Porta'm = porta + em = bring me
• after a vowel, em is reduced to 'm

Compare:

• Em portes un bol. = You bring me a bowl.
• Porta'm un bol. = Bring me a bowl.

So this is normal imperative pronoun placement.

Yes. Porta'm is the informal singular imperative, used with tu.

The verb is portar = to bring. Its imperative here is:

• porta = bring! (to one person, informal)

Other possibilities would be:

• Porti'm = bring me... (formal singular, vostè)
• Porteu-me = bring me... (plural or polite plural, vosaltres/vostès, depending on context)

A useful extra point: with negative commands, the pronoun goes before the verb:

• No em portis aquest. = Don’t bring me this one.

In standard Catalan, altre in the singular usually appears with a determiner such as un, una, el, la, etc.

So:

• un altre bol = another bowl
• l'altre bol = the other bowl

That is why un altre bol is the normal form here.

Also, bol is masculine, so you get:

• un altre bol
• uns altres bols (plural)

Because perquè is the conjunction meaning because.

Catalan distinguishes several similar-looking forms:

• perquè = because
• per què = why / for what reason
• per a què = what for / for what purpose

So in this sentence, perquè is correct because it introduces the reason.

Because Catalan can omit the noun when it is already clear from context.

Here, aquest stands for this one, meaning this bowl. So:

• en aquest = in this one / in this bowl

This is very natural once the object has already been mentioned:

• Porta'm un altre bol, perquè en aquest...

The listener already knows that aquest refers to the current bowl.

Hi is a very common Catalan weak pronoun referring to a place or location. Here it means something like in it / there.

The verb cabre often uses hi when talking about where something fits:

• No hi cap. = It doesn’t fit in there / in it.

In this sentence, the location en aquest has been moved to the front for emphasis or topic:

• En aquest no hi cap tota l'amanida.

Catalan often keeps hi even when the place phrase is also stated. This can feel redundant to an English speaker, but it is very normal in Catalan.

You can think of it roughly as:

• In this one, the whole salad doesn’t fit in it.

That sounds repetitive in English, but it is standard Catalan structure.

Here, cap is the 3rd person singular present of the verb cabre, which means to fit.

So:

• hi cap = it fits in it / there is room for it
• no hi cap = it doesn’t fit

This cap is unrelated to the other common word cap, which can mean:

• head (noun)
• any / no in negative contexts, as in cap problema = no problem

So this is one of those cases where the same written form has different meanings.

Useful forms of cabre here are:

• cap = fits
• caben = fit (plural)

Because l'amanida is a feminine singular noun, and tota agrees with it:

• l'amanida = the salad
• tota l'amanida = the whole salad / all the salad

Even though a salad contains many pieces, it is being treated as one whole quantity, so the verb is singular:

• no hi cap tota l'amanida

If the subject were plural, the verb would also be plural:

• No hi caben totes les pomes. = All the apples don’t fit in it.

Because Catalan often puts the subject after verbs like cabre, especially in sentences about whether something fits, exists, appears, etc.

So:

• En aquest no hi cap tota l'amanida.

sounds natural and idiomatic.

You could rearrange it, but the emphasis changes. For example:

• Tota l'amanida no hi cap en aquest bol.

That is understandable, but the original sentence feels more natural because it first points to the container and then says what does not fit in it.

The verb would change from cap to caben, because it must agree with a plural subject.

Compare:

• En aquest no hi cap tota l'amanida.
  singular subject: tota l'amanida

• En aquest no hi caben totes les verdures.
  plural subject: totes les verdures

So cap = singular, and caben = plural.