The smallest meaningful or grammatical unit in a language. Morphemes are not necessarily the same as words. The word ‘cat’ has one morpheme, while the word ‘cats’ has two morphemes: ‘cat’ for the animal and ‘s’ to indicate that there is more than one. Similarly, ‘like’ has one morpheme, while ‘dislike’ has two: ‘like’ to describe appreciation and ‘dis’ to indicate the opposite. Morphemes are very useful in helping students work out how to read and spell words.