I think you are mistaken. The word en is always pronounced [ɛn], the word één is pronounced [e:n] and the word een is has four possible pronunciations: [nən nə ən ə].
When do Flemings say which pronunciation?
1. In Standard Dutch: always [ən]
2. In the dialects:
-Masculine words: nə or nən
nə man, nən auto, nə wagen, nən gameboy, nən dag, nə fiets
(You say nən before words that start with a vowel or T, H, B, D or English g. Otherwise you say nə. However, it depends on the dialect, because in the east you will hear more nə than nən)
-Feminine words: always ən
ən vrouw, ən koe, ən kip, ən kat
-Neuter words: ən or ə
ə koekske, ə pakske, ən boek, ə gebouw, ə meisje
(You say ən before words that start with a vowel or T, H, B, D or English g. Otherwise you say ə. However, it depends on the dialect, because in the east you will hear more ə than ən for neuter words)
3. In tussentaal: As you likely know, many Flemings don't speak Standard Dutch, but they don't speak the original local dialect either. They speak something in between, which is known as tussentaal and depends on the individual. I would say that many Flemings (including me) use the following system:
Het-words (neuter): ən or ə (as mentioned above)
This is because the words nə and nən are considered dialectal, so they are replaced by ən, but the word ə is kept because it sounds almost like ən. Many people are unaware that they speak like this.
Thanks for your reply RedArrow. I was very unclear with the title of this thread. I didn't mean the words "en" and "een" at all; I was talking about whenever "-en-" appears in a word, either word internally or word finally.
Specifically, words or morphemes that end in -en (as a result of inflection or otherwise) seem to lack a final "n" in a lot of dialects, so "een lied zigen" sounds more like "een lied zinge", and "tegenstelligen tussen de..." sounds like "tegestellinge tusse de...". I notice this a lot less in some Flemish dialects that I've heard.
I'm very interested in this (sadly), so any light you or any other natives or near-natives could shed would be greatly appreciated.
the N is usually dropped. However, the N is not dropped if the next word starts with a vowel (or H in most of Flanders).
However, in and around West-Flanders and also in the North of the Netherlands, people still pronounce the N.
Secondly, any other N is kept. This means:
Keulen (N is kept in German placenames)
Maarten (N is kept in names of people)
Leuven (N is kept in any placename, at least in the standard language)
Ik teken (N is kept in the verb stem!)
één teek, twee teken (this N is dropped, because it's a plural!)
So in many accents, "ik teken" and "twee teken" sound differently.
This has already been discussed in other threads. I recommend you to use the search function.