Tu prends ce modèle en coton ou celui en laine ?

Because this is the very common spoken way to ask a question in French.

French has several ways to ask questions:

• Tu prends ce modèle en coton ou celui en laine ? → common in everyday speech
• Est-ce que tu prends ce modèle en coton ou celui en laine ? → also very common
• Prends-tu ce modèle en coton ou celui en laine ? → correct, but more formal or written

So tu prends ... ? is normal conversational French.

Yes, prendre literally means to take, but in this context it often means something more like:

• to choose
• to go for
• to have
• to buy

So in a shopping situation, Tu prends ce modèle... ? naturally means Are you taking/choosing this model... ?

French uses:

• ce before most masculine singular nouns
• cet before masculine singular nouns that start with a vowel sound
• cette for feminine singular nouns

Since modèle starts with the consonant sound m, you use ce:

• ce modèle

Compare:

• ce pantalon
• cet article
• cet homme

In this sentence, modèle means model, style, or version of an item.

In shopping French, it often refers to a particular design or type of product, especially clothing or household items.

So ce modèle en coton means something like:

• this cotton model
• this version in cotton
• this style in cotton

Here, en means made of or in a certain material.

So:

• en coton = made of cotton
• en laine = made of wool

This is very common in French when talking about materials:

• une chemise en coton
• un pull en laine
• une table en bois

Because after en to express material, French usually does not use an article.

So you say:

• en coton
• en laine
• en soie
• en cuir

Not:

• en le coton
• en la laine

This is just the standard French pattern for materials.

Celui is a demonstrative pronoun. It means that one or the one and replaces a masculine singular noun that has already been mentioned.

Here, instead of repeating modèle, French says:

• ce modèle en coton ou celui en laine ?

That means:

• this cotton model or the wool one?

So celui avoids repeating modèle.

Because celui must match the noun it replaces, and modèle is masculine singular.

French demonstrative pronouns change by gender and number:

• celui = masculine singular
• celle = feminine singular
• ceux = masculine plural
• celles = feminine plural

Since modèle is masculine singular, celui is the correct form.

Yes. Tu is the informal singular you.

It is used with:

• friends
• family
• children
• people you know well
• sometimes customers, depending on the situation and level of formality

If you wanted the formal or plural version, you would say:

• Vous prenez ce modèle en coton ou celui en laine ?

Prends is the present tense of prendre, with tu:

• je prends
• tu prends
• il/elle prend

In this sentence, the present tense is used for a current choice or immediate decision, which is very natural in both French and English.

Yes, it could, but it sounds less natural because it repeats modèle unnecessarily.

For example:

• Tu prends ce modèle en coton ou ce modèle en laine ?

This is understandable, but French usually prefers:

• Tu prends ce modèle en coton ou celui en laine ?

Using celui makes the sentence smoother and more natural.

Yes. The word ou means or, and the sentence presents two choices:

• ce modèle en coton
• celui en laine

So the speaker is asking the listener to choose between two options.