The flashcard app above can help you to learn the vocabulary of body parts.
Many body parts have other common names. For instance, the navel is less formally called the bellybutton, and the belly is less formally called the tummy. The small finger is often called the pinkie.
A regular plural is one that is obtained by adding "s" or "es" to a singular noun; an irregular plural is one that is not obtained this way. English has many irregular plurals, and the plurals of some of the words in the flashcards are irregular; examples are the plurals of "calf", "foot", and "tooth". You can practice all of these using the flashcard app that begins this section.
Remarkably, the word "hair" is used in its singular form to refer to hair when it is effectively uncountable, as it is for the hair on one's head or one's body. When the number if hairs is easily counted, the plural form, "hairs", is used.
The dictation app above can help you learn the spellings of the terms introduced in the previous section.