Learn Dutch: Zij is het meisje.

Both zij and ze mean "she". Zij is the stressed or emphatic form, while ze is the unstressed form. You use zij when you want to put focus on the person—for example, pointing out that "SHE is the girl (and not someone else)."

A girl is female, so why does the sentence use the neuter article het instead of de?

In Dutch, all diminutive words (words ending in -je, -tje, etc., which usually mean a "little" version of something) are always neuter and must take the article het. Because meisje ends in -je, it is grammatically a het word, regardless of the person's actual gender!

If meisje is a diminutive because of the -je, what is the original word?

It comes from the older Dutch word meid (which means maid or young woman). By adding the ending -je (or -sje in this case), it became meisje. Today, meisje is just the standard everyday word for "girl", but it keeps the grammar rules of a diminutive.

is looks exactly like English! Does it belong to a regular verb?