xkcd #2942: Fluid Speech
Alt text:
Thank you to linguist Gretchen McCulloch for teaching me about phonetic assimilation, and for teaching me that if you stand around in public reading texts from a linguist and murmuring example phrases to yourself, people will eventually ask if you're okay.
I had to think of a ghetto accent "I'm ga'a fuck you up, mate".
So, it's not like there's no movement in that single syllable. A mild attempt is made at pronouncing two syllables, by having the back of the tongue shortly touch the roof of the mouth. But for properly pronouncing an "n", the front of your tongue needs to touch the roof of your mouth, and that's certainly not happening.