/ŋ/ is a nasal consonant sound made by touching the tongue against the velum. The same place as /k/ and /g/:
When you pronounce /ŋ/, noise escapes through the nose. Just as it does with /m/ and /n/.
The /ŋ/ phoneme does not appear in the English alphabet. But it’s easy to spot because it’s normally one of:
n + g = THING /θɪŋ/
n + k = BANK /baŋk/
n + c = ZINC /zɪŋk/
/ŋ/ in Connected Speech
If /n/ ends a word such as IN and the next word begins with /k/, the words will join and the /n/ turns into /ŋ/:
SEPARATELY: /ɪn ˈkɛnjə/
The same occurs with /g/:
This process is called ASSIMILATION.
/ŋ/ in Accents
Words that end in NG such as:
are pronounced without the final /g/ in most accents of the UK and Ireland, though you will hear the /g/ in areas of the Midlands and North of England:
In words such as:
the G is removed in most accents (throughout the UK and Ireland):
pronounced with /ɪn/ NOT /ɪŋ/.
In Received Pronunciation (RP) / General British (GB), the endings are pronounced /ɪŋ/ and this is the pronunciation you’ll find in British dictionaries.
But some people pronounce them /ɪn/ in informal situations and /ɪŋ/ in formal situations.