The morpheme

What is a morpheme? How do we understand the concept?

In traditional formalist views of language, the morpheme is the smallest meaningful part of a word, that is, it is not divisible any further without loosing its meaning.

The English noun meaningfulness can be divided as follows: mean-ing-ful-ness

In that example, the hyphens are meant to represent morpheme breaks or boundaries and the four parts each represent a morpheme. The first one, mean is the root of the noun while the other three are derivational suffixes. In this case, the root is verbal from the verb mean as in:

(1) I really mean what I said!

The next, -ing- derives a noun from the verb resulting in mean-ing, the next suffix -ful- derives an adjective from the noun and finally -ness- turns the adjective into a noun.

Of the four morphemes, the verbal root can be said to be a free morpheme because, as we saw in (1). The derivational suffixes are bound morphemes because, although they carry individual meaning, they cannot occur alone and still be meaningful. While we can pronounce such sequences as *ful-ness but they do not make any sense because this combination is not grammatical in the English langauge. Ungrammaticality is shown by an asterisk in front of a word.

However, we do not understand such morphemes as mean in (1) just based on their structure. We need to see all of the context in (1) in order to know that we are dealing with a verb mean and not, say, an adjective akin to evil or another adjective akin to avarage. Likewise, we do not know whether the morpheme -s in plumber-s (in spoken language) signifies possession or plurality.
Furthermore, just as morphemes are meaningless outside of their context, so are most utterances. Consider for instance example (2).

(2) I gave it to him, but he still won't tell me how to get there.

We can deduce that in (2) some object was given by somebody who is of male sex, and that the first person grammatical subject who gave it has a desire to go somewhere, and was expecting the recipient of the object, to tell him how to get there. However, since we have no knowledge of the context of utterance, there are many missing pieces in the puzzle, as shown by the vagueness of my previous deduction.