Do not mix up written and spoken vowels!
There are 9 different written vowels in German (a, e, i, o, u, ä, ö, ü, y) but 30 different vowels in spoken German if you count long and short vowels as distinct vowels and if you count stressed and unstressed versions as different sounds too. You should at least differentiate between long and short vowels, because for example the only difference between the spoken words
- Stahl (pronunciation: [ʃtaːl]) (English: steel) and
- Stall (pronunciation: [ʃtal]) (English: barn, stable)
is the length of the vowel. There are many other minimal pairs where only the length of a vowel makes the difference between two words.
I didn't find any minimal pairs where the only difference is the stress, but still stressed and unstressed vowels sound different, and using a stressed vowel when it should be unstressed or vice verse would result in a wrong pronunciation. For example in the word Kosmos the only difference between the two o-sounds is the stress. (Both of them are short [ɔ] sounds, but the first is stressed, the second is not).
But on the other hand the spoken vowel in März is the very same as the first vowel in Mercedes and also the first vowels in Type and Tüte are equal although they are written with different letters. But the letter y often also is pronounced like i (Party, Hobby), and in rare cases a written y even becomes a diphthong (y is pronounced as [aɪ̯] in Nylon)
Diphthongs are always spoken as two vowels where you slide from one vowel to the other. This takes some time, and so all diphthongs are longer than short monophtongs.
Standard German has only four diphthongs (in German dialects there are much more):
(Note, that Leib and Laib are pronounced equally although they are written different and mean different things. Leib = body; Laib = loaf)
But there are also many spoken diphthongs that are not written as diphthongs (i.e. as two vowels) because the written consonant r, when it comes after a vowel, very often is pronounced as a schwa-sound and builds the second sound of a diphthong:
- [eːɐ̯] - er
- [iːɐ̯] - ihr
- [oːɐ̯] - Ohr
- [uːɐ̯] - Uhr
- (some more)
(Note, that the letter h in the last 3 examples is just a length marker that is silent, so all 4 words consists of a diphthong only without any consonant)
When you now compare the first 4 non-schwa-diphthong with the 4 examples of schwa diphthongs, you will notice, that the first sound of the non-schwa-diphthong was a short vowel, while in the other examples it was a long vowel, which means, that also diphthongs come in two different lengths. So, we have:
- short monophthongs: Stall
- short diphthongs: Haus
- long monophthongs: Stahl
- long diphthongs: Ohr
(Note, that the length of diphthongs does not strictly depend on the schwa-sound. »er« in the prefix »ver-« is a short schwa-diphthong: verlieren [fɛɐ̯ˈliːʁən])
As far as I know there is only one German word with a triphthong:
It is an onomatopoetic word that tries to imitate the typical sound of a cat (AE: meow, BE: miaow) from it derived is the verb miauen
ich - ach
The German ch-Sound can be [ç] like in ich or [x] like in ach.
Use [ç] when it appears in the suffix -chen (Mädchen = [ˈmeːtçən]) or when it comes after vowels, that are articulated in the front of the mouth:
When ch comes after a vowel that is produced in the back of the mouth you should use [x]: