Lesquelles de ces vis faut-il utiliser pour cette vieille chaise ?

Which of these screws should be used for this old chair?

Breakdown of Lesquelles de ces vis faut-il utiliser pour cette vieille chaise ?

• la chaise: the chair
• pour: for
• de: of
• falloir: to be necessary
• cette: this
• ces: these
• vieux: old
• utiliser: to use
• la vis: the screw
• lesquelles: which

Questions & Answers about Lesquelles de ces vis faut-il utiliser pour cette vieille chaise ?

What does lesquelles mean here?

Lesquelles means which ones.

It is used when the noun is already understood or already mentioned. Here, it refers to vis (screws), so instead of repeating the noun, French uses lesquelles.

A simpler comparison:

• Quelles vis faut-il utiliser ? = Which screws should we use?
• Lesquelles de ces vis faut-il utiliser ? = Which ones of these screws should we use?

So lesquelles is basically standing in for these screws.

Why is it lesquelles and not lesquels?

Because vis is a feminine plural noun in French: une vis, des vis.

The forms of lequel change to match gender and number:

• lequel = masculine singular
• laquelle = feminine singular
• lesquels = masculine plural
• lesquelles = feminine plural

Since vis is feminine plural here, the correct form is lesquelles.

Why is there de in lesquelles de ces vis?

After lequel / laquelle / lesquels / lesquelles, French often uses de to mean of or among.

So:

• lesquelles de ces vis = which ones of these screws
• more naturally in English: which of these screws

This is a very common pattern:

• Lequel de ces livres... ? = Which of these books...?
• Laquelle de ces portes... ? = Which of these doors...?

Why does vis look the same in singular and plural?

Because vis is one of those French nouns whose singular and plural forms are spelled the same:

• une vis = a screw
• des vis = screws

The number is shown by the article or determiner, not by changing the noun itself.

In this sentence, ces vis clearly means plural because ces means these.

What does faut-il mean?

Faut-il comes from the verb falloir, which means to be necessary or to have to.

The basic statement is:

• Il faut utiliser... = It is necessary to use... / You have to use...

In question form with inversion, it becomes:

• Faut-il utiliser... ? = Is it necessary to use... ? / Should one use... ?

In this sentence, the idea is something like:

• Which of these screws should you use...?
• Which of these screws must be used...?

Does il in faut-il refer to a person?

No. The il in il faut does not refer to a specific person.

This is an impersonal construction. It works a bit like English it in it is necessary.

So:

• il faut does not mean he must
• it means it is necessary or one must

That is why faut-il here is not asking about a man. It is just the question form of an impersonal expression.

Why is the word order faut-il instead of il faut?

Because French often forms more formal questions by inversion: the verb comes before the subject pronoun.

Statement:

• Il faut utiliser...

Question:

• Faut-il utiliser... ?

This is standard and correct, especially in written French or careful speech.

A more conversational version would often be:

• Lesquelles de ces vis est-ce qu'il faut utiliser pour cette vieille chaise ?

Both are correct, but the original sentence sounds a bit more formal or polished.

Could I say Quelles vis faut-il utiliser... instead?

Yes, absolutely.

• Quelles vis faut-il utiliser pour cette vieille chaise ? = Which screws should be used for this old chair?
• Lesquelles de ces vis faut-il utiliser pour cette vieille chaise ? = Which of these screws should be used for this old chair?

The difference is:

• Quelles vis... asks generally which screws
• Lesquelles de ces vis... asks you to choose from a specific set already in front of you

So the original sentence is more specific.

Why is pour used in pour cette vieille chaise?

Here pour means for, in the sense of intended for, suitable for, or to use with this chair.

So pour cette vieille chaise means:

• for this old chair
• for use on this old chair
• suitable for this old chair

If you used sur instead, that would focus more literally on physical location, like on the chair. But pour is the natural choice when you are talking about choosing the right screws for that item.

Why is it cette vieille chaise?

Both words must agree with chaise, which is feminine singular.

So:

• ce = masculine singular
• cette = feminine singular
• ces = plural

And:

• vieux = masculine singular
• vieille = feminine singular

Because chaise is feminine singular, French uses:

• cette chaise
• vieille chaise

So cette vieille chaise means this old chair.

Why does vieille come before chaise?

In French, many adjectives come after the noun, but some common ones often come before it. Vieux / vieille is one of them.

So French normally says:

• une vieille chaise = an old chair

not usually:

• une chaise vieille

This is part of a broader pattern with some common adjectives of beauty, age, size, and goodness, which often come before the noun.

Is this sentence natural French, or does it sound very formal?

It is natural and correct, but it sounds a bit careful or formal, especially because of faut-il inversion.

A native speaker could definitely say it, especially in writing or in a clear, deliberate question.

More everyday spoken French might be:

• Lesquelles de ces vis est-ce qu'il faut utiliser pour cette vieille chaise ?
• Quelles vis il faut utiliser pour cette vieille chaise ? (more casual, and less formal)

So the original sentence is good French, just slightly more formal than casual conversation.