Après le shampooing, la coiffeuse lui passe un peigne fin dans les cheveux.

In French, shampooing is a noun, so it normally takes an article. That is why you get après le shampooing = after the shampoo / after washing the hair.

French often uses an article where English would not:

• après le dîner = after dinner
• avant le cours = before class
• pendant la journée = during the day

So après le shampooing is the natural French phrasing.

Yes. In French, un shampooing can refer to:

• the shampoo product, or
• the act of washing the hair, depending on context.

In this sentence, après le shampooing most naturally means after the hair wash or after shampooing.

French borrowed this word from English, but the spelling is shampooing.

La coiffeuse means the female hairdresser. French nouns usually have grammatical gender, and for jobs referring to people, the form often changes depending on whether the person is male or female:

• le coiffeur = the male hairdresser
• la coiffeuse = the female hairdresser

So this sentence specifically tells you the hairdresser is a woman.

Here, lui means to him or to her.

It is an indirect object pronoun. The sentence is literally structured like this:

• la coiffeuse = the hairdresser
• lui passe = passes to him/her / runs for him/her
• un peigne fin = a fine comb
• dans les cheveux = through the hair

In more natural English, you would say:

• The hairdresser runs a fine comb through his/her hair.

French uses lui because the action is being done to that person.

In French, object pronouns usually come before the conjugated verb.

So:

• la coiffeuse lui passe...

not:

• la coiffeuse passe lui...

This is a basic French pronoun pattern:

• Je lui parle. = I speak to him/her.
• Elle lui donne un livre. = She gives him/her a book.
• La coiffeuse lui passe un peigne fin...

English learners often want to place the pronoun after the verb, but standard French does not do that here.

Yes, passer often means to pass, but it has several meanings. In this sentence, it means something like:

• to run
• to pass
• to draw

as in to run a comb through someone’s hair.

So passer un peigne dans les cheveux means:

• to run a comb through the hair

This is very idiomatic French. It does not mean the hairdresser is simply handing someone a comb.

French adjectives can come before or after the noun, depending on the adjective. Here, fin comes after the noun:

• un peigne fin

This means a fine comb, more specifically a fine-toothed comb.

Many descriptive adjectives in French come after the noun:

• une table ronde = a round table
• un sac noir = a black bag
• un peigne fin = a fine comb

So this word order is normal.

In this context, it usually means a fine-toothed comb.

That is the kind of comb with very closely spaced teeth. French often uses peigne fin in exactly that sense, especially when someone is carefully combing through hair.

So although the literal translation is fine comb, the natural English meaning is usually fine-toothed comb.

Literally, dans les cheveux means in the hair. But in this kind of context, French uses dans where English would often say:

• through the hair
• in the hair

So:

• passer un peigne dans les cheveux = to run a comb through the hair

It is just the normal French way to express this action. A very literal word-for-word translation sounds odd in English, but the French wording is natural.

French normally uses les cheveux in the plural to mean hair on the head.

Even though English often uses hair as an uncountable noun, French usually treats it as plural when talking about someone’s head of hair:

• Elle a les cheveux longs. = She has long hair.
• Il se lave les cheveux. = He washes his hair.

A single cheveu means a single hair.

And poils usually refers to body hair, fur, or bristles, not the hair on someone’s head.

French often uses the definite article with body parts where English uses a possessive adjective.

So instead of saying:

• his/her hair

French often says:

• the hair

especially when the owner is already clear from the sentence.

Here, lui already tells you whose hair it is, so les cheveux is enough:

• la coiffeuse lui passe un peigne fin dans les cheveux

This is very common in French:

• Je me lave les mains. = I wash my hands.
• Il a mal à la tête. = His head hurts / He has a headache.

It could, depending on context, because passer un peigne fin dans les cheveux can suggest using a fine-toothed comb very carefully, which is something people do when checking for lice or removing them.

However, it does not have to mean that. It could also simply describe careful combing after washing the hair.

So the sentence itself is neutral, but the expression peigne fin can sometimes create that association.