Velar plosives /k/ and /g/

/k/ and /g/ are velar plosives since the sounds happen at the velum (also called soft palate). /k/ is unvoiced and is the counterpart to the voiced /g/. To make the /k/ sound, open the mouth, lift the back of the tongue, push the tongue against the back of the throat, and then let the tongue down with a puff of air. Air is briefly prevented from leaving the vocal tract when the back of the tongue lifts and presses against the soft palate. The sound is aspirated when the air is released. To make the /g/ sound, do as you do with /k/, but this time voice the sound.

Notice that the place of production of these velar plosives, /k/ and /g/, changes depending on the type of vowels. When they are followed by back vowels (/u/ and /ʊ/), these velars are produced normally, i.e., in the back of the mouth. However, when they are followed by front vowels (e.g., /i/ and /ɪ/), they are produced somewhere in the middle or in front of the mouth (e.g., “keep, Kim” vs “cool, cook”) 

Several alphabet letters can make the /k/ sound: k, ck, c, ch, x, qu/que.

k spelling:

kid, thinking, bake
ck spelling: 

back, sick, truck

c spelling: 

cart, cool, caught

x spelling (The ‘x’ is pronounced as /k/+/s/)” 

fix, fox, next, box
ch spelling: 

chorus, choir, ache, chaos, school

qu spelling (The ‘qu’ is pronounced as /k/+/w/):

quit, quiet, quick, question, queen

When the ‘que’ spelling is at the end of the word, it is pronounced only as /k/: for example, antique, unique 

These are minimal pairs of /k/ and /g/.

/k/, /g/ minimal pairs

came game

card guard

class glass

cold gold

could good

cave gave

clean glean

cot got

crate great

crease Greece

cap gap

cash gash

coast ghost

coat goat

come gum

con gone

crab grab

cram gram

creek Greek

crepe grape

crew grew

croup group

crow grow

curly girly

cut gut

kill gill

cane gain

clad glad

clamor glamor

clue glue

cod god

crane grain

crease grease

creed greed

crime grime

krill grill

cape gape

core gore

crate grate

crowned ground

crumble grumble

cunning gunning

curd gird

cussed gust

kale gale

In the following pairs, /k/ and /g/ appear at the end of the words. When this happens it can be hard to hear which phoneme is used. The vowel length is the  key. The vowel sound is longer with the voiced /g/ than with the voiceless /k/. 

back bag

pick pig

clock clog

dock dog

duck dug

frock frog

muck mug

block blog

brick brig

buck bug

crack crag

jock jog

lack lag

leak league

lock log

luck lug

pluck plug

rack rag

sack sag

smock smog

snack snag

tack tag

chuck chug

flock flog

hack hag

hock hog

jack jag

knack nag

puck pug

shack shag

snuck snug

stack stag

tuck tug

whack wag

wick wig

/k/, /g/ sentences

These are sentences with /k/ and /g/.

The dog in the jacket can lick the girl on the back.

Kick the big green ball.

The big cake cooled in the kitchen.

The school chorus will sneak in a pig for the Queen of England.

Get a clean fork from the sink.

Please be quiet so I can ask you a quick question.