Tip: See my list of the 
MostGerman alphabet contains three additional symbols for vowels, which are often misunderstood or mispronounced by learners whose mother tongue does not contain the sounds they represent. We will discuss each of them separately.
However, we should deal with a common misconception first, namely that ä, ö, and ü are always long. It stems from the fact that these are indeed more commonly found in long syllables than in short ones, but this is by far not a rule. One elementary principle you should remember is:
For example:
- Männer (men) is pronounced /ˈmɛnɐ/, not /ˈmɛːnɐ/
- können (to be able to) is pronounced /ˈkœnən/, not /ˈkøːnən/
- Müller (miller) is pronounced /ˈmʏlɐ/, not /ˈmyːlɐ/
So, what exactly is the difference between a and ä, o and ö, and u and ü?
Ä
Ä is the easiest case to deal with in terms of pronunciation. It is pronounced the same as “e” in the English word “bet” (IPA: /ɛ/). Since “e” in German is also often pronounced the same, you may be asking why we need ä at all. For example, Bett (“bed” in German) is pronounced the same as “bet” in English.
There are two reasons why ä is useful. First, it is often used to reveal that two words are related. It is easier to see that Männer is the plural of Mann or Blätter the plural of Blatt (leaf, sheet) than if they were written “Menner” and “Bletter”.
The second reason is the more important one. When the letter “e” in German is located in an open stressed syllable (i.e. when there are no consonants at the end), it is pronounced as /eː/. This sound does not exist in standard American or British English in isolation. It only exists in the diphthong /eɪ/, which we can find in words like “late”, “hey”, “same”. To pronounce /e/ properly, try to say English “hey”, but freeze your tongue in the middle of saying “ey”.
For example, listen to the word Wesen (“being”). It is pronounced /ˈveːzn/, because the syllables are We-sen (remember that “e” is pronounced /eː/ in open syllables?). The same happens also when “e” is followed by an “h”, e.g. wehrend (weh-rend), /ˈvɛːʁənt/, meaning “resisting”.
The problem is: What if you want the long /ɛː/ sound (/ɛ/ as in “bet”) instead? Many German words contain this sound, but there is no way to denote it using the letter “e”. The solution: Use “ä” instead. The distinction is often important, for example:
- während /ˈvɛːʁənt/ means “during”
- wehrend /ˈveːʁənt/ means “resisting” (the present participle of wehren)
Ö
Ö is slightly more complicated for English speakers in terms of pronunciation. It is similar to the vowel in the British pronunciation of “bird”, “heard”, “curd” (IPA: /ɜː/), but with lips rounded. To say it, say /ɛ/ (as in “bet”) with your tongue but shape your lips as if saying “oo” in “boot”. In other words, if your lips are saying “boot” but your tongue is saying “bet”, you are approximately saying ö. There is also a slight difference between the pronunciation of a short ö /œ/ and a long ö /øː/. Listen to these examples:
- Short: können (to be able to), öffnen (to open), Löffel (spoon).
- Long: Löwe (lion), Möhren (carrots), Flöte (flute).
Ü
Ü is often pronounced as /jʊ/ by English speakers, but such pronunciation is not correct in German. To pronounce ü correctly, round your lips as if you were to say “oo” in “cool” or “stool”, but move your tongue to say “ee” (as in “see”) instead (but don’t move your lips). Again: say “cool” with your lips and “keel” with your tongue. What you are saying now is ü. Again, there is a slight difference between the short ü /ʏ/ and the long ü /yː/. Listen to the following examples:
