Put your hand in front of your mouth. Feel the puff of air on the "nk" sound.
Raise your tongue in the back of your mouth and then release it with a puff of air.
Raise your tongue in the back of your mouth, use your voice while a little air comes out your nose.
The "nk" sound
The "nk" sound
The "ng" sound
The "ng" sound
NOTE: "nk" and "ng" are consonant blends. In blended sounds, you pronounce both letters quickly together in one syllable.