4.3.1 Free and bound morphemes

　 Some morphemes like water, desire, work, able, and there constitute words by themselves. They are free morphemes when they are components of words. Other morphemes like de-, dis-, -ish, -ing, -ness, and -ly are never used independently in speech and writing. They are always attached to free morphemes to form new words. These morphemes are called bound morphemes.

　 The distinction between a free morpheme and a bound morpheme is whether it can be used independently in speech or writing. Take the word dewater, for example. The word is composed of two morphemes. De- is bound, water is free. The distinction can be tested by the fact that native speakers of English would not accept (c) as grammatical:

--- What are you going to do with the plants?
--- (a) I am going to water them.
　　(b) I'm going to dewater them.
　　(c) *I'm going to de them.

　 Some English bound morphemes may have the same form as free morphemes, but they are distinctive in meaning. Some, as a word, has the same spelling as -some, which is a suffix, as found in tiresome, handsome, troublesome, etc. Step and step- may serve as another example. The morphemes which are the same in form but distinctive in meaning are actually homographs (which will be further discussed in chapter 6).

　 Free morphemes were traditionally called roots, and bound morphemes affixes. Modern linguists find that there are a number of components of words which appear like roots but cannot be used independently in speech or writing. For example, ceive in receive, perceive, conceive, deceive, and mit in admit, commit, permit, remit, submit, transmit, are not meaningful out of the words. The meaning of the form depends on the entire word of which it is a part. Modern linguists are inclined to treat them as morphemes and call them bound roots.