"Which dog is yours?"

Translation: Lequel est votre chien ?

[deactivated user]

My answer was: quel chien est vôtre.
The response: You need the article "le" here. Quel chien est le vôtre ?
Not sure why le (the) precedes vôtre

[Ripcurlgirl]

Because le/la is part of the grammatical construction. The noun here being possessed, chien, is masculine, therefore le vôtre = yours.
la vôtre = yours (fem).

Read the tips and notes here

[deactivated user]

Not understanding why le/la is part of the grammatical construction. Could I get around it by always using lequel instead of quel?

[Sitesurf]

Possessive pronouns all use a definite article:

• le mien, la mienne, les miens, les miennes
• le tien, la tienne, les tiens, les tiennes
• le sien, la sienne, les siens, les siennes
• le nôtre, la nôtre, les nôtres
• le vôtre, la vôtre, les vôtres
• le leur, la leur, les leurs.

Besides, "quel" is used when there is a choice among several to many options and "lequel" is used when there are only 2 or 3 options.

• Quel est ton chien ? = Which is your dog?
• Lequel est ton chien ? = Which one (of these 2/3) is your dog?

[deactivated user]

Why is the definite article "le" not required with ton but is required with vôtre?

[CommeuneTexane]

These are two different parts of speech. In the first example vôtre with the circumflex is a possessive pronoun. We would translate that as yours, and it always has le/la/les in front of it.

C'est le vôtre = It's yours.

The second example votre is a possessive adjective and is always followed by a noun, in this case, dog.

C'est votre chien (no circumflex) = It is your dog.

This is true for le/la/les tien(nes) and ton/ta.

Ton/ta are always followed by a noun while le tien/la tienne/les tiens/les tiennes are always proceeded by the corresponding article.

C'est le tien = It's yours.
(for a singular masculine noun like chien)

C'est la tienne = It's yours.
(for a singular feminine noun like fleur)

C'est ton chien = It's your dog. / C'est ta fleur = It's your flower.

[deactivated user]

Thanks CommeuneTexane for the detailed explanation

[CommeuneTexane]

You're welcome!