Parts of the body (ręka, noga)

The basic set

Polish	English	gender
hand, arm	ręka
hand, arm	feminine
leg, foot	noga
leg, foot	feminine
finger, toe	palec
finger, toe	masculine
ear	ucho
ear	neuter
mouth, lips	usta
mouth, lips	plural only

Two things to notice. Polish ręka covers both hand and arm, and noga covers both leg and foot — the English split does not exist. And usta is grammatically plural: it has no singular, so it always takes a plural verb.

Saying what hurts

to hurt, to ache

boleć is to hurt. The part of the body is the SUBJECT — the thing doing the hurting — so the verb agrees with it:

Noga boli. — The leg hurts. Ucho boli. — The ear hurts.

Two more states

sleepy

senny (sleepy) and thirsty

spragniony (thirsty) join głodny, chory and zmęczony from the earlier lessons. All are adjectives, so they agree with the person: Jestem senny / Jestem senna.