A affix - an additional element placed at the beginning or end of a root, stem, or word, or in the body of a word, to modify its meaning. a morpheme that is attached to a word stem to form a new word.
A prefix goes at the beginning. A prefix is placed at the beginning of a word to modify or change its meaning.
A suffix goes at the end of a word.
A suffix is a group of letters placed at the end of a word to make a new word. A suffix can make a new word in one of two ways:
1. inflectional (grammatical): for example, changing singular to plural (dog > dogs), or changing present tense to past tense (walk > walked). In this case, the basic meaning of the word does not change.
2. derivational (the new word has a new meaning, "derived" from the original word): for example, teach > teacher or care > careful
The morphemes in the list on the left contribute in some way to the insertion of the words in a particular grammatical context, so that the word agrees with this context in terms of tense, number, person etc. The changes in meaning that these morphemes bring are minimal. These are called inflectional morphemes, note that these are all suffixes.
The morphemes in the list on the right bring considerable semantic changes to the word, often word class is changed, e.g. modern (adj.) > modernise (v.); drink (v.) > drinkable (adj.); nation (n.) > national (adj). These are called derivational morphemes because they are used to derive new words. Derivational morphemes may be prefixes or suffixes.
"The difference between derivational and inflectional morphemes is worth emphasizing. An inflectional morpheme never changes the grammatical category of a word. For example, both old and older are adjectives. The -er inflection here (from Old English -ra) simply creates a different version of the adjective. However, a derivational morpheme can change the grammatical category