English contains many words that look similar but have completely different meanings and uses. Woman and women are two of the most commonly confused examples. Because the spelling differs by only a couple of letters, even experienced writers can sometimes hesitate when deciding which form to use. Understanding the difference is actually quite simple: woman is singular, while women is plural. Once you learn this basic rule, choosing the correct word becomes much easier.Why Woman and Women Are ConfusingMost English nouns form their plural by adding -s or -es. For example, book becomes books, car becomes cars, and class becomes classes. However, woman is an irregular noun, so its plural does not follow the usual pattern. Instead, the spelling changes internally from woman to women. This unusual change is one of the main reasons people sometimes mix up the two forms when writing quickly.The difference is similar to the familiar change from man to men. The vowel changes instead of simply adding a letter at the end. Because the two words are visually similar, writers may accidentally use the plural form when talking about one person or use the singular form when referring to a group. Paying attention to whether you're talking about one person or more than one person is the easiest way to avoid the mistake.The Basic DifferenceThe most important rule is simple: woman refers to one adult female, while women refers to two or more adult females. For example, you would say, “That woman is a talented writer” when talking about one person. If you're talking about several people, you would say, “Those women are talented writers.” When deciding between women-or-woman always ask yourself whether the sentence refers to one person or multiple people.The surrounding words in a sentence can also provide useful clues. If you see words such as a, one, each, or every, the singular form woman is usually needed. On the other hand, words such as two, three, several, many, both, and numerous indicate that the plural form women should be used.When to Use WomanUse woman when you're referring to a single adult female. For example, “A woman called the office this morning,” “The woman is waiting outside,” and “Every woman received a certificate” are all correct sentences. In each case, the sentence refers to one person at a time, so the singular form is appropriate.One easy clue is the article a. You can say a woman, but you cannot say a women. The word a is used with singular countable nouns, which means that the noun following it must be singular. Therefore, if you see a immediately before the word, woman is the correct choice.