Learn Romanian: Acest copac este foarte vechi.

Acest means "this" and is used before masculine and neuter nouns in the singular. Because copac (tree) is a masculine noun, we must use acest. If the noun were feminine, like carte (book), we would use această.

Does acest always come before the noun?

Yes, this specific form of "this" always goes before the noun. When you use it at the front like this, the noun stays in its simple dictionary form without any "the" endings attached to it.

The word vechi ends in an "i". Does that mean it is plural?

Not in this case! While "i" is usually a plural ending in Romanian, the adjective vechi (old) naturally ends in an "i" even in its singular form. Since copac is singular (one tree), vechi is just matching it using its normal dictionary form.

Can I use vechi to describe an old person, too?

No, vechi is mostly used for objects, places, or concepts (like a tree, a building, or a friendship). If you want to say a person or animal is old, you must use the word bătrân instead.