Use a mirror and notice how your mouth opens wider for the "y" sound. Touch your throat to feel the vibration for these two sounds.
Smile and pull back on your tongue so that it touches the sides of your back teeth. Use your voice.
Put the tip of your tongue behind your top front teeth. Push a short burst of air out while using your voice.
The "y" sound
The "y" sound
The "j" sound
The "j" sound
NOTE: "lk" is a consonant blend. In blended sounds, you pronounce both letters quickly together in one syllable.