Inflection Vs Derivation

Inflection

Derivation

It is mostly defined as a type of affix which differs grammatical forms of the same lexeme. It is also known as a word formation to different grammatical categories.

It focuses on the study and creation of new words, these words are mostly formed with smaller parts (words)

Examples:
Tense
Case
Voice
Aspect
Person
Mood

Examples:
Black-Bird=Blackbird
Hope-Ful=Hopeful
Play-Ful=Playful

Derivarion in Grammar

In morphology, derivation is the process of creating a new word out of an old word, usually by adding a prefix or a suffix.

Derivational Prefixes

Derivational Suffixes

Derivational suffixes, on the other hand, usually change both the meaning and the word class; that is, a suffix is often added to a verb or adjective to form a new noun with a different meaning

Derivational prefixes do not normally alter the word class of the base word; that is, a prefix is added to a noun to form a new noun with a different meaning

Differences between Inflectional and Dericational

Both inflectional and derivational morphemes are suffixes. They are bound morphemes following a root. Inflection and derivation are therefore, the sub-categories of suffixes. But they differ from each other

In inflection “suffix” is affixed to a root. For example, in “agreed” and “agrees,” “d” and “s” are suffixes and do not allow any further affixation of a suffix. Such suffixes which we do not allow further affixation are called inflections or inflectional suffixes. The suffixes which may be followed by other suffixes are called derivational suffixes. For example, “ment” “able” are derivational suffixes in “agreement” and “agreeable” because both can be followed by other suffixes and can, for instance, become “agreements” and “agreeableness” after the addition of the suffixes “s” and “ness” to agree+ment and agree+able respectively

We have to remember that prefixes are always derivational. For instance, in the words; disobey, impossible, etc “dis” and “im” are prefixes. Since “dis” and “im” help to construct new words “obey” and “possible” they are derivational.

Inflectional suffixes are “terminal”(ending) and their termination never changes the class (parts of speech) of the root, for example in “sweeter” and “sweetest”, the termination of –“er” by “est” does not change the parts of speech; both the form remain adjectives. “come” is a verb in “they come late” and if we add an inflectional suffix “ing” we get the form “coming” as in they are coming which is still a verb.

References:
Fraser Alexander, 2016. Inflection & Derivational Morphology, CIS, Ludwig-Maximilians-Universität München
Literary Articles, 2013. Differences between inflection and derivation.