Learn Finnish: Näkemiin on helppo, mutta hyvästi on vaikea. - Goodbye is easy, but farewell is hard.

Näkemiin is the standard everyday way to say goodbye, and it implies that you will meet again. It comes from the verb nähdä (to see). Hyvästi is much more final, like saying "farewell." You generally only say hyvästi when you don't expect to see the person ever again.

Does hyvästi come from the word hyvä (good)?

Yes! The ending -sti is a common ending used to turn adjectives into adverbs, similar to adding "-ly" in English. Historically, saying hyvästi was a way of wishing that things go well for someone as they depart forever.

Why does näkemiin end in -iin?

This ending comes from a grammar case that shows motion "into" something. You don't need to memorize the complex grammar behind it at this level, but it helps to know that näkemiin literally translates to "into seeing." It is just a fixed, shortened way of saying "until we see each other again."

Why are there no words for "a" or "the" in this sentence?

Finnish doesn't have articles like "a", "an", or "the" at all. The sentence is literally "Goodbye is easy, but farewell is hard." The meaning is simply understood from context, so you never have to worry about translating English articles into Finnish!