Learn French: Ce meuble est très vieux, mais je l'aime beaucoup. - This piece of furniture is very old, but I like it a lot.

In English, "furniture" is an uncountable word used for any amount. In French, un meuble is a countable word meaning one specific piece of furniture (like a chair or desk). If you have several pieces, you use the plural les meubles.

Why does vieux end in an "x" if we are only talking about one piece of furniture?

The masculine adjective vieux (old) is irregular and naturally ends in an "x" in its singular form. Because of this, its masculine plural form stays exactly the same.

In je l'aime beaucoup, what does the l' replace?

The l' is a pronoun meaning "it", standing in for ce meuble. It is normally spelled le, but because the verb aime starts with a vowel, the "e" is dropped to make l'aime.

Does je l'aime beaucoup mean "I love it a lot"?

When talking about objects, aimer usually means "to like". Adding beaucoup specifically translates to "to like a lot". If you want to say you "love" an object, it is better to use the verb adorer.