"Morphology is commonly defined as
the study of the internal structure of words and the rules governing the formation of words in a language"

What do we mean when we say we know a word? To put it another way, what does knowing a word mean?

Knowledge of a word is connected with different types of
information encoded in our mental dictionary (lexicon).


We can list the kinds of information we have mastered about a word as follows:

Pronunciation and Meaning

We have learned a sound (pronunciation) and a
meaning for every word we know. 

Every word consists of a sound-meaning unit, so every word in our lexicon is stored together with a pronunciation and a
meaning, maybe several meanings.

 There is also an arbitrary relationship  between sounds and meanings. Consequently, we may encounter words that have the same
pronunciation and different meanings (for example, bare and bear) and words that
have the same meaning and different sounds (for example, sofa and couch).

Grammatical Category:

 We also store other information about a word, such as whether it is a verb, a noun, an adjective, an adverb, a conjunction, or a
preposition. This kind of information identifies the grammatical class of the word.
For example, in the sentences I love John and John is the love of my life, the
word love is both a verb and a noun according to our knowledge of its grammatical
or syntactic class.

Orthography / Spelling:



Every literate speaker of a language also stores
information about how to spell the words they know. However, not every speaker knows – or has to know 
– the etymology of a word he or she knows.
 In daily life, we may sometimes talk about the origin 
and history of words such as coffee or
yoghurt, but this kind of historical information
 encoded in our mental lexicon is not truly 
representative of our knowledge of words.

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