An inflection sounds painful, but it’s actually just linguistic terminology for a suffix (or word ending) that performs a grammatical function.
In Present Day Standard English, we use inflections to perform the following functions, amongst others:
– to pluralise nouns.
Usually, it’s an -s inflection (e.g. one girl, two girls)
A few nouns, though, form their plural with an -en inflection (e.g. oxen, brethren, children)
A few nouns form their plural with zero inflection (e.g. sheep, fish, deer)
Some nouns of foreign origin pluralise with a foreign inflection (e.g. one paparazzo, two paparazzi; one cactus, two cacti; one criterion, two criteria; one gateau, two gateaux)
A few nouns do not form their plural with inflections, at all, but by changing a medial vowel (e.g. goose, geese; tooth, teeth; foot, feet; man, men; mouse, mice)
– to signify possession
We use an -s inflection to show something belongs to someone or something
e.g. The cat’s whiskers. The box’s lid. Sherlock’s brilliance.
– to signify the third person singular of a present simple verb
Yes, it’s the ever-popular -s inflection, again!
e.g. I sing, you sing, we sing, they sing, but she sings; I laugh, you laugh, we laugh, they laugh, but he laughs
– to signify the past tense of weak verbs in the simple aspect
The -ed inflection
e.g. I worked yesterday. I spotted a tiger in the High Street last week.
Many varieties of English use inflections slightly differently.
Creoles (such as Jamaican Creole, Belize Kriol, Gullah, Kamtok etc) usually omit inflections and perform the grammatical function in other ways. This is because Creoles are descended from pidgins – basic contact languages which allowed speakers of different languages to communicate for some immediate practical purpose (usually for trade or to give instructions to servants or slaves). Any grammatical features not absolutely necessary for understanding are stripped away in a pidgin.
e.g. In “Daisy got five friend”, the determiner “five” already makes clear that it’s plural, so the -s inflection (friends) is unnecessary.
In “He like pizza”, the pronoun “he” already makes it clear that it’s third person singular, so the -s inflection (likes) is unnecessary.
In “I work yesterday”, the temporal adverb “yesterday” makes clear that it is in the past, so the -ed inflection (worked) is unnecessary.
Some varieties of English, for example, African-American Vernacular English (AAVE) form the past tense periphrastically, not inflectionally (that is, they say “I did cook dinner” or “I done cook dinner”, adding an extra word – the auxiliary verb “did” or “done” – before the main verb to show that it’s in the past, instead of adding an -ed inflection to the end of the verb)
Language change over time
Earlier varieties of English have more inflections than PDSE does.
For example, in Early Modern English, verbs in the simple aspect have a second person singular inflection, -st/-est. e.g. I love thee. Thou lovest me. I walked to college. Thou walkedst, too.
Early Modern English also uses a different inflection for the third person singular from the one we use today. We use -s (He loves her. She hates him. It hurts.) In the 1600s, they used -eth, instead (He loveth her. She hateth him. It hurteth.)
The -s inflection started off as a Northern dialect feature (probably borrowed from the Vikings, who spoke a language called Norse), but gradually replaced -eth as the Standard English form.
Also, look out for other inflections we don’t have today, if you’re reading an old text.
The adjectival -(e)n inflection which still just about survives in words like “golden” (=made of gold), “woollen” (=made of wool) and “wooden” (=made of wood) used to be far more widespread, with “leathern” (=made of leather), “strawen” (=made of straw), “silken” (=made of silk), “glazen” (=made of glass), “silvern” (=made of silver) etc.