In the name of Allah,the Most Compassionate,the Most Merciful,
According to yule (1996), Morphemes(i.e minimal units of meaning or grammatical functions) are of two categories;
- Free morphemes;including lexical & functional morphemes,and
- Bound morphemes; including derivational & inflectional ones.
As for the inflectional morphemes, the play no role in the change of the word class.Their main function is to show the grammaticality of the words.
According to Yule (1996), there are 8 types of inflections, as follows:
- 2 ( -er & -est ) used with adjectives.
- 2 used with nouns (-s plural,-'s possessive)
- 4 used with verbs (-s 3rd person sg ,-ed past tence ,-en past participle & -ing present progressive)
You have to take into account that inflections can never come in the initial position of any word .
If so , they will be considered prefixes, and naturally parts of derivational morphemes .