Dans la cabine, ma fille dit que ce pantalon lui va mieux que l’autre.

In French, un pantalon is normally singular, even though in English we often use the plural pants or trousers.

• un pantalon = a pair of pants / trousers
• ce pantalon = these pants / this pair of pants

So even if the English meaning is plural-looking, French treats it as one item of clothing.

Here, la cabine usually means the changing room or fitting room in a shop.

So dans la cabine means in the fitting room.

A learner might expect cabine to mean only cabin, but in clothing-shopping contexts it often refers to the place where you try clothes on.

French often uses the definite article when the thing is already understood from the situation.

So in a clothes shop, la cabine means the fitting room, the one relevant in the situation. It does not necessarily mean there is only one fitting room in the whole shop; it just means the fitting room being talked about.

Compare:

• dans une cabine = in a fitting room / in one of the fitting rooms
• dans la cabine = in the fitting room / in the changing room

Because dire que means to say that.

• ma fille dit = my daughter says
• ma fille dit que... = my daughter says that...

In French, que is very commonly used to introduce a full clause after verbs like dire, penser, croire, savoir, etc.

So:

• Elle dit qu’il vient. = She says that he’s coming.
• Je pense que c’est vrai. = I think that it’s true.

Use ce before a masculine singular noun that begins with a consonant sound.

• ce pantalon
• ce livre
• ce garçon

Use cet before a masculine singular noun that begins with a vowel sound or a mute h:

• cet homme
• cet été
• cet hôtel

Since pantalon begins with the consonant sound p, it must be ce pantalon.

Here, lui means to her.

In the sentence, it refers back to ma fille:

• ma fille dit que ce pantalon lui va mieux...
• literally: my daughter says that these pants go better to her...

More natural English would be something like fit her better or suit her better.

So lui is an indirect object pronoun meaning:

• to him
• to her

depending on the context.

Because object pronouns usually come before the conjugated verb in French.

So:

• Ce pantalon lui va bien.
• Je lui parle.
• Ça me plaît.

This is a very common French word order pattern.

Here:

• lui = indirect object pronoun
• va = form of aller

So lui va is the normal order.

Yes, aller often means to go, but it also has another common meaning with clothes: to suit, to look good on, or to fit well.

Examples:

• Cette robe me va bien. = This dress suits me / fits me well.
• Le bleu lui va bien. = Blue suits him/her.
• Ce pantalon lui va mieux. = These pants fit/suit her better.

So in clothing contexts, aller à quelqu’un often means to suit someone.

Because mieux is the comparative form of bien, while meilleur is usually an adjective meaning better.

Here, mieux modifies the verb phrase va:

• va bien = fits/suits well
• va mieux = fits/suits better

So:

• Ce pantalon lui va mieux. = These pants suit her better.

Use meilleur / meilleure / meilleurs / meilleures when better describes a noun:

• un meilleur pantalon = a better pair of pants
• une meilleure idée = a better idea

But here we are not describing the pants as better in general; we are saying they fit her better, so mieux is correct.

L’autre means the other one.

In this sentence, it stands for the other pair / the other pair of pants. French often leaves out the repeated noun when it is obvious from context.

So:

• ce pantalon lui va mieux que l’autre
• literally: these pants suit her better than the other one

The full version could be:

• ...mieux que l’autre pantalon

But French usually prefers the shorter version when the noun is already clear.

Because l’autre means the other one, usually referring to a specific alternative already known in the situation.

In a fitting room, the speaker probably has two pairs of pants in mind:

• this one = ce pantalon
• the other one = l’autre

By contrast:

• un autre = another one, some other one

So:

• ce pantalon ... que l’autre = this pair ... than the other one
• ce pantalon ... qu’un autre would sound different and less specific

Yes. Aller bien / aller mieux with clothing can cover both ideas:

• the item fits properly
• the item suits the person’s appearance better

So ce pantalon lui va mieux can mean:

• it fits her better
• it suits her better
• it looks better on her

The exact nuance depends on context.

In most normal contexts, ma fille means my daughter.

French fille can mean girl or daughter, but with a possessive like ma, it very often means my daughter.

So in this sentence, that is the most natural interpretation.

It would become:

• Dans la cabine, elle dit que ce pantalon lui va mieux que l’autre.

That is grammatically correct, but now there are two feminine references:

• elle dit = she says
• lui va mieux = suits her better

Very often, both would refer to the same person, but the full noun ma fille makes the sentence clearer.

A few useful points:

• Dans sounds roughly like dahn with a nasal vowel.
• cabine is pronounced ka-been, not like English cabin.
• fille sounds like fee-y or feey, not like fill.
• dit is pronounced dee.
• pantalon has nasal vowels: roughly pahn-ta-lon.
• lui sounds like lwee.
• mieux sounds roughly like myuh.
• l’autre has the l’ because autre begins with a vowel.

A smooth reading would be approximately:

Dahn la ka-been, ma fee-y dee kuh suh pahn-ta-lon lwee va myuh kuh lohtr.

It breaks down like this:

• Dans la cabine = location
• ma fille dit = main clause
• que ce pantalon lui va mieux que l’autre = subordinate clause

Inside that second part:

• ce pantalon = subject
• lui = indirect object
• va = verb
• mieux = comparative adverb
• que l’autre = comparison

So the sentence structure is very typical French:

[place], [subject] + [verb] + que + [new clause].