"He teaches us the words."
Isn't "nous" plural, thus giving apprend an "s". I've made this mistake on other exercises so an explanation is appreciated.
No, the conjugation of "apprendre" needs to match that of the subject (il in this sentence).
J'apprends, Tu apprends, Il/Elle apprend,
nous apprenons, vous apprenez ils/elles apprennent
The "s" that you see at the ends of verbs doesn't have much to do with how plural a word is, it is just the conjugation (adjectives are a different story).