When you take a yoga class (especially Ashtanga, Vinyasa, and Jivamukti classes), sometimes the instructor will call out the names of the poses in their original language, Sanskrit. Here's a list of some body parts in Sanskrit, so you can get familiar with them. Knowing these Sanskrit words really helped me to remember the names of certain yoga poses.
Pada - foot or leg, as in Utthita Hasta Padangusthasana A (Extended Hand to Big Toe pose or Standing Hand to Big Toe A)
Angustha - big toe, as in Supta Padangustasana (Sleeping Big Toe pose)
Hasta - hand, as in Padahasthasana (Foot to Hand pose)
Sirsa - head, as in Sirsasana (Headstand)
Janu - knee, as in Janu Sirsasana (Head to Knee pose)
Karna - ear, as in Karnapidasana (Ear Pressure Pose)
Anga - limb, as in Trianga Mukha Eka Pada Paschimottanasana (3 Limbs Facing 1 Foot Western Intense Stretch Posture or Half Hero Forward Bend)
Pincha - chin, as in Pincha Mayurasana (Forearm Stand)
Sava - a corpse, dead body, as in Savasana (Corpse pose)
If you're lucky, your instructor will only use the Sanskrit names of poses, so after hearing them over and over again, they'll become ingrained in your brain. It's still okay to call poses by their English name too - it doesn't matter what you call them, just as long as you're doing them, right?