Introductory Ancient Greek Language/Lesson 2

Every Greek word that begins with a vowel will have something called a breathing mark.

These look like apostrophes and can be either rough or smooth.

If the breathing mark is smooth then it is shaped exactly like an apostrophe and comes before the vowel.

If the breathing is rough then it is an apostrophe curved in the opposite direction. (Curved like this <. As opposed to the smooth curve like this >.)

So what does this all mean? If a breathing is rough then the word is pronounced as if there were an /h/ in front of it.

Thus, the Greek word for 'sleep' ὕπνος will be pronounced as [hupnos].