Definition
Word formation process (also called morphological process) is a means by which new words are
  produced either by modification of existing words or by complete innovation, which in turn become
  a part of the language.
  Types of Word Formation Processes
  Different types of word formation processes are employed to create new words. However, all word
  formation processes basically bring either inflectional or derivational changes. Therefore, inflection
  (also called inflexion) and derivation are the two core processes of word formation. Inflection differs
  from derivation to the following extent:
  Inflection                                       Derivation
  Produces grammatical variants of the same Produces a new word on the basis of an
  word.                                     existing word.
  Modifies a word to express different
                                                   Changes the word class (also called parts
  grammatical categories such as tense,
                                                   of speech; form class; lexical class;
  mood, voice, aspect, person, number,
                                                   syntactic category).
  gender and case.
  Does not change the meaning of a word.           Modifies the meaning of the root. For
  For example: determine→ determines,              example: modern → modernize (to make
  determining, determined.                         modern).
  The major word formation processes include but are not limited to the following:
  Affixation
  It is a word formation process wherein an affix is attached to a root (also called stem; base) to form
  a new word. A root is a free morpheme (also called unbound morpheme) that can appear alone. On
  the other hand, an Affix is a bound morpheme which never occurs by itself, but is always attached
  to some free morpheme and can be either inflectional or derivational. An Inflectional affix modifies
  the form/grammatical category of a word, i.e., tense, person, number, gender, case, etc. For
  example: rat → rats. Contrariwise, a derivational affix modifies the parts of speech of the root, while
  leaving the grammatical category unchanged. In this way there is a change of meaning of the
  root. For example: write → writer.
  In English there are two types of affixations:
1. Prefixation: In this morphological process words are formed by adding an affix to the front of
   a root. The type of affix used in this process is referred to prefix. For example: un +
   tidy → untidy
2. Suffixation: In this morphological process words are formed by adding an affix to the end of a
   root. The type of affix used in this process is referred to suffix. For example: fear +
   less → fearless
    Conversion
    This refers to the change of function or parts of speech of a word without adding an affix.
    Conversion is also called zero derivation or null derivation since the functional change is brought
    about by supplementing an invisible affix. Sometimes it is also called functional shift. Typically
    conversion is made from “noun to verb” and from “verb to noun”. Less frequently, conversion is also
    done from “adjective to verb” and “adjective to noun”. For instance:
    Noun to Verb:
    access
    email
    film
    name
    shape
    Verb to Noun:
    attack
    alert
    hope
    increase
    visit
    cover
    Adjective to Verb:
    brown
    black
    slow
    Adjective to Noun:
    crazy
    nasty
    Back-formation
    Back-formation is a morphological process in which new word is created by extracting affixes from
    another word. In this way it is the reverse of affixation, in which affixes are added. Back-formation
    is also different from clipping since it brings a change in the parts of speech or the word's meaning.
    For example: the noun insertion has been back-formed into verb insert by removing the suffix ion.
    Clipping
    As the name suggests, clipping is the word formation process in which a word is reduced to a
    shorter form. With a sharp contrast to back-formation, clipping keeps the original word meaning
    intact. These words are very common in everyday speech. For instance: lab is the clipped form
    of laboratory. . There are four types of clippings:
1. Back clipping: (also called final clipping; apocope) it involves the truncation of end of a word
   as in ad from advertisement.
2. Fore-clipping: (also called initial clipping; apheresis) it is the removal of the beginning of a
   word as in phone from telephone.
3. Middle clipping: (also medial clipping; syncope) it is the extraction of the beginning and end
   of a word as in flu from influenza.
4. Complex clipping: is removing multiple parts from multiple words as
   in cablegram from cabletelegram.
    Compounding
    Also called composition, by this process two or more than two words are combined together to
    create a single word, having a single idea and function. In English there are compound nouns,
    compound adjectives, and compound verbs. Customarily compound words are spelt as single word,
    or as two or more hyphenated words, and even as two or more separate words. For example:
    life + style → lifestyle
    mother + in + law → mother-in-law
    shopping + mall → shopping mall
    There are no specific rules for hyphenated compounds. Generally, some new and original compound
    nouns are hyphenated, but the hyphen is ignored when they become more familiar. However, there
    are some compound adjectives that are always hyphenated. For instance: state-of-the-art. The
    hyphen is often retained when two vowels come together, such as: Co-operation. Hyphens are often
    used to tell the ages of people and things, for example: 10-year-old. The general rule is that words
    are combined with hyphens to avoid confusion.
    Borrowing
    This refers to the words adopted from other languages. There are two types of borrowings:
1. Loan-word: By this process a word is borrowed from another language without translating it
   into the target language. For example: the phrase tour-de-force is borrowed directly from
   French, which means a masterly or brilliant feat.
2. Loan-translation: Also known as calque, a morphological process wherein a word or phrase
   from another language is borrowed by literally translating it into the target language. For
     example: the phrase point of view has been translated into English from the French
     phrase point de vue.
    Coinage
    Also called invention, is a morphological process by which new words are invented. Sometimes
    popular trademark names of various products are adopted by people so extensively that they
    ultimately become the everyday words of language. For example:
    Heroin
    Aspirin
    Escalator
    Xerox
    Kerosene
    Nylon
    Band-Aid
    Vaseline
    Margarine
    Videotape
    Again, some words are being invented due to rapid cultural changes and the spread of information
    technology, mass media, internet, etc. For example:
    Google
    Blog
    Hotspot
    Netbook
    Tablet
    Tweet
    Emoticon
    Smartphone
    Blending
    Blending (also called portmanteau) is a morphological process in which the parts of two or more
    words are combined together to form a new word. Usually the parts consist of the beginning of one
    word and the end of the other word(s). Typically, the meaning of the blended word reverberates
    with the meanings of the original words. For example:
    breakfast + lunch → brunch
    motor+hotel → motel
    However, blending should not be confused with compounding, which combines two words without
    truncation of parts of the roots of the blended words.
    Acronyms
    These words are formed with the initial letters or each of the major parts of a word or a longer
    phrase. With a few exceptions, acronyms are usually capitalized. Some linguists confuse acronyms
    with initialisms, which are also abbreviations formed in the similar manner as the former. In
    essence, there is a sharp difference between the two. In language, an acronym is pronounced as a
    single word rather than just a sequence of individual letters, which is characteristic of initialisms. For
    example:
    Acronyms:
    United Nations Educational, Scientific and Cultural Organization → UNESCO
    Light Amplification by Stimulated Emission of Radiation → Laser
    International Criminal Police Organization → Interpol
    Initialisms:
    Personal Computer → PC
    Asian Development Bank → ADB
    Liquid Crystal Display → LCD