The first thing to remember about gender in grammar is that it is not a biological category. It is a grammatical category. In language, it is not people who have gender, but rather words that do (and specifically, nouns and things associated with nouns, like pronouns, participles, and adjectives). One cannot tell from biological gender what the grammatical gender will be, because most of the things in our universe don't have biological gender at all — books, bottles, burnings, blunders, burdens, and bubbles have nothing to do with biological gender. In Greek, all such things must have grammatical gender however. Those things that do have biological gender generally have the corresponding grammatical gender, but there are a number of exception to that principle. For example, the two most common words for "child" (teknon and paidion) are neuter.

When translating Greek nouns, gender is unimportant, for English has no way of, or interest in, expressing the gender of nouns. When translating Greek pronouns, gender is more important, for English does make a distinction for the third person singular (he, she, or it). Otherwise, gender is unimportant.