I’m a non-native speaker and I have always pronounced all words with syllables ending in ‘n’ followed by a /k/ sound with the velar nasal /ŋ/. For example:
think / increase (v+n) / income / incomplete.
This was just acquired naturally without any intentional training.
(I understand that words ending with ‘nk’ like ‘think’ do get the velar /ŋ/ sound, and that’s something that gets explained to ESL learners).
I was surprised when I recently found out that many of these words are transcribed as /nk/ rather than /ŋk/ in the dictionaries (Oxford, Cambridge, Merriam-Webster for example), and I have a few questions about it:
- Do all of you native speakers follow these dictionary patterns, or are there some among you who follow a pattern similar to mine?
- What’s the difference or the rule that makes a word like ‘inkling’ get an /ŋ/ while a word like ‘include’ get an /n/? And generally is there rules for which words with ‘nk’/’nc’ sequences get an /n/ sound and which get an /ŋ/ sound?
- I played the word ‘conclude’ repeatedly on different dictionaries, and they all sound as having an /ŋ/ to my ear. Are these dictionary transcriptions universally accurate!? Do you hear it as an /n/ when you listen to it? Can native speakers normally distinguish the two sounds in all contexts?
- When I say a word like ‘conclude’ I find it much easier to pronounce it with an /ŋ/, because with an /n/sound it’s switching from a velar to an alveolar and back to velar, while with an /ŋ/ sound it’s all velar. Do you native speakers pronounce it with an /n/ sound?!
- For people with ESL teaching experience among you, do you bring up this topic with your students?
(And thanks for your patience!)
As mentioned in the comments, this previous question has overlap with yours: Why do dictionaries transcribe the nasal in 'think' and 'language' with /ŋ/, yet 'input' and 'inbox' with /n/, not /m/? I don’t want to copy my answer there, so please go to the linked page to read it.
To address your numbered questions:
According to many accounts, English speakers may optionally pronounce coda /n/ as [ŋ] before any syllable starting with velar plosive, even when there is a word boundary. So in this way, [ŋ] would be possible not only in words like income, but even in phrases like “in ten cars”.
However, I’ve read that the “[ŋ]” produced from /n/ by a process of “gestural overlap” like this may actually be different, either acoustically or maybe just articulatorily, from the [ŋ] sound used for the phoneme /ŋ/.
This kind of gestural overlap across syllable boundaries does not affect the phonemic status of /n/. For example, I have /n/ and not /ŋ/ in the word nightingale, which is detectible from my pronunciation of the /t/: it’s a voiceless stop for me, as in the word lighten, rather than being lenited and voiced as in the word lighting.
The same kind of gestural overlap is supposed to cause /n/ to be pronounced like [m] before labial stops or the labial nasal, /t/ to be pronounced like [p] before labials and like [k] before velars, and /d/ to be pronounced like [b] before labials and like [g] before velars.
I don’t think information about these kinds of gestural overlap is useful to ESL students.
For derived words, refer to the pronunciation of the original word. For example, clinking, banker, linkage have /ŋ/ just as clink, bank, link have /ŋ/.
It’s probably also true to say that /nk/ is impossible as a syllable-final cluster (that is to say, /n.k/ only occurs with an intervening syllable boundary), but the problem is that English syllable boundaries are difficult to place and people disagree about where they fall.
For non-derived words, intervocalic “nk” is probably /ŋk/, although there might be exceptions.
I don’t know the actual etymology of the word inkling, but it looks like it ends in either a diminutive ending -ling or a frequentive suffix -le followed by the suffix -ing. Removing -ling gets you ink, which would have to have /ŋk/ because, as you mentioned, /nk/ is not possible word-finally.
(also 4) The distinction between /n/ and /ŋ/ at the end of the prefixes in- or con- before a velar consonant, as in the word conclude, is not too important to native speakers. I don’t know the figures about how well people can distinguish the sounds in this context.
I think every native speaker would agree that /n/ and not /ŋ/ is the phoneme that shows up in compound words like pancake or pincushion.