In linguistics, word formation is an ambiguous term^[1] that can refer to either:

• the processes through which words can change^[2] (i.e. morphology), or
• the creation of new lexemes in a particular language

A common method of word formation is the attachment of inflectional or derivational affixes.

Examples include:

• the words governor, government, governable, misgovern, ex-governor, and ungovernable are all derived from the base word (to) govern^[3]

Inflection is modifying a word for the purpose of fitting it into the grammatical structure of a sentence.^[4] For example:

• manages and managed are inflected from the base word (to) manage^[1]
• worked is inflected from the verb (to) work
• talks, talked, and talking are inflected from the base (to) talk^[5]

Examples includes:

• etc. from et cetera

An acronym is a word formed from the first letters of other words.^[6] For example:

• NASA is the acronym for National Aeronautics and Space Administration
• IJAL (pronounced /aidʒæl/) is the acronym for International Journal of American Linguistics

Acronyms are usually written entirely in capital letters, though some words originating as acronyms, like radar, are now treated as common nouns.^[7]

Initialisms are similar to acronyms, but where the letters are pronounced as a series of letters. For example:

• ATM for Automated Teller Machine
• SIA for Singapore International Airlines^[1]

In linguistics, back-formation is the process of forming a new word by removing actual affixes, or parts of the word that is re-analyzed as an affix, from other words to create a base.^[5] Examples include:

• the verb headhunt is a back-formation of headhunter
• the verb edit is formed from the noun editor^[5]
• the word televise is a back-formation of television

The process is motivated by analogy: edit is to editor as act is to actor. This process leads to a lot of denominal verbs.

The productivity of back-formation is limited, with the most productive forms of back-formation being hypocoristics.^[5]

A lexical blend is a complex word typically made of two word fragments. For example:

• smog is a blend of smoke and fog
• brunch is a blend of breakfast and lunch.^[6]
• stagflation is a blend of stagnation and inflation^[1]
• chunnel is a blend of channel and tunnel,^[1] referring to the Channel Tunnel

Although blending is listed under the Nonmorphological heading, there are debates as to how far blending is a matter of morphology.^[1]

Compounding is the processing of combining two bases, where each base may be a fully-fledged word. For example:

• desktop is formed by combining desk and top
• railway is formed by combining rail and way
• firefighter is formed by combining fire and fighter^[5]

Compounding is a topic relevant to syntax, semantics, and morphology.^[2]

Linguists argue that hashtags are words and hashtagging is a morphological process.^[8][9] Social media users view the syntax of existing viral hashtags as guiding principles for creating new ones. A hashtag's popularity is therefore influenced more by the presence of popular hashtags with similar syntactic patterns than by its conciseness and clarity.^[10]

There are processes for forming new dictionary items which are not considered under the umbrella of word formation.^[1] One specific example is semantic change, which is a change in a single word's meaning. The boundary between word formation and semantic change can be difficult to define as a new use of an old word can be seen as a new word derived from an old one and identical to it in form.

• Neologism