The sound of Dutch vowels depend on whether they are in open or closed syllables.
A syllable is closed if it in a consonant sandwich (e.g. “bed”) and open if not (e.g. “ga”).
In Dutch, in addition to the vowels “a”, “e”, “i”, “o”, “u”, and “y”, there are a number of diphthongs.
"oe" sounds like the "oo" in "tooth"
"eu" sounds like the "ay" in day with rounded lips, or like the "eu" in the French word "feu"
"ei/ij": these sounds are like a combination of "eh" and "ee", similar to the "ay" in "day"
"ui" is tricky, but can be described as a short "a" sound followed by a "u" sound.
"uw" is a long Dutch "u" sond with a slight "w" sound
"ou" and "au" sound similar to the "ou" in "loud"
"aai" sounds like a long "a" sound followed by a long "i"
"eeuw" long "e" sound followed by the "uw" diphthong from above
"ooi" long "o" sound followed by a long "i"
"oei" combination of "oe" and "ie" ("ie" is pronounced the same as a long "i")
