The word “each” refers to a singular subject within a group of countable nouns, so it is technically a singular word. Some American English speakers may be unclear on this technicality due to the subject-verb agreement rules that apply to the use of “each.”

Each, which refers to every person or thing individually, is grammatically singular. Use each before a singular noun followed by a singular verb. Each person is important. Each story is based on real events. When used alone as a pronoun, each is again singular. Each is based on real events.

As a pronoun, each is considered singular, so it is traditionally paired with singular verbs. (Grammar Rules for Writers.) For instance, "each of the athletes" may indicate multiple athletes in the phrase, but "each" is a singular occurrence of those athletes.

Under the traditional rule, the indefinite pronoun each is always singular and takes a singular verb. Each of the golfers wants to win the PGA. Each of us wishes for success. Some usage panels disagree. Consider this usage note on Dictionary.com: