An inflectional morpheme is a suffix that’s attached to a word (a noun, verb, adjective, or adverb) to assign a grammatical property to that word, like its tense, number, possession, or comparison. Inflectional morphemes in English have  the bound morphemes -s (or -es), ‘s (or s’), -ed; -en; -er, -est, and -ing. Suffixes may even do double- or triple-duty. For instance, – s can note possession, make count nouns plural, or put a verb in the third-person singular tense. Likewise, the suffix -ed can make past participles or past-tense verbs.