Inflection (or inflexion) is a piece added to a word to express variations in grammar. The added bits are called affixes. They are prefixes (in front), suffixes (at the end) and infixes (in the middle). They are added to the root, the part of the word which does not change.
Some languages such as Latin or Sanskrit have complex inflections that they apply to most of their words. Others, such as English, are less inflected. Some, such as Mandarin Chinese, use no inflections.
Examples in English:
Write, writes, wrote, written are tenses of the verb to write. Inflecting a verb is called conjugation.
Sing, sang, sung
Dog, dogs is a noun inflected for number. Inflecting a noun is called declension.
Foot, feet
Mouse, mice
Child, children
Dog's, dogs' are nouns in the genitive case, which means that the word after are owned by the dog or dogs.
I, me, and myself are all cases, or different word forms, of the first-person pronoun.
my can be used as adjective and mine can be used as pronoun. Hence can be considered as use of inflection apart from example of derivation