As they say, a Morpheme is the smallest linguistic unit of language which has meaning.

Putting it simply, if you take a word like

unquestionable

you can break it down into 3 morphemes:

un = not
question = ask
able = able to be

Each of the 3 morphemes has a meaning and if you take one away, the meaning of the word changes.

Morphemes can’t be broken down any further; they are the smallest they can be.

Are Morphemes Syllables?

Often, but not always. The following are words broken down into their morphemes:

banana
tele + vision
dog + s
anti + dis + establish + ment + arian + ism
me
John + ‘s

Sometimes then morphemes are the same as syllables, but occasionally not.

Are Morphemes Words?

Sometimes, but not always. The morphemes which go to make up

star + ship
bed + room

can stand alone. They are known as free morphemes.

On the other hand, the first and last morphemes in these words cannot:

un + concern + ed
dis + passion + ate

These are known as bound morphemes and often occur at the beginning or end of words as affixes.

Morphemes and TEFL

Sometimes it’s useful to refer to morphemes in TEFL although to keep things simple you should probably not use that word and instead just talk about affixes (prefixes and suffixes).

Explain, for example, that various affixes have specific meanings:

anti– = against, e.g. antiserum
non– = not or without, e.g. nonconformist

–less = without, e.g. airless
–ious = with the qualities of, e.g. melodious

This will be fine for most classes and will help your students work out the meanings of some unknown words.

Spoken vs Written Morphemes

In spoken language, morphemes are composed of phonemes (the smallest linguistically distinctive units of sound).

In written language morphemes are composed of graphemes (the smallest units of written language).

Useful Links

Phoneme‏‎s in English – about the morphemes in spoken language

Affix‏‎es in English – about affixes (prefixes and suffixes)