English: Processes of word formation

The English language uses many processes of word formation, so probably your question refers to the main processes, plural. These include compounding, blending and the related analogy, and acronyms. Compounding is the combination of two nouns to form another. Usually it is written as a single word. Example: “carport.”

▪ Blending 
Blending is the combination of parts of two words to create a new word with a different meaning, or coinage. One author who notably coined many words is Lewis Carroll, especially in his poem “Jabberwocky.” Example: “Slithy” usually considered to blend “slimy” and “lithe.” Others pronounce it with a short I, however, claiming “slither” is a component.
In blending, part of one word is stitched onto another word, without any regard for where one morpheme ends and another begins. For example, the word swooshtika 'Nike swoosh as a logo symbolizing corporate power and hegemony' was formed from swoosh and swastika. The swoosh part remains whole and recognizable in the blend, but the tika part is not a morpheme, either in the word swastika or in the blend. The blend is a perfect merger of form, and also of content. The meaning contains an implicit analogy between the swastika and the swoosh, and thus conceptually blends them into one new kind of thing having properties of both, but also combined properties of neither source. Other examples include glitterati (blending glitter  and literati) 'Hollywood social set', mockumentary (mock and documentary) 'spoof documentary'.
The earliest blends in English only go back to the 19th century, with wordplay coinages by Lewis Carroll in Jabberwocky. For example, he introduced to the language slithy, formed from lithe and slimy, and galumph, (from gallop and triumph. Interestingly galumph has survived as a word in English, but it now seems to mean 'walk in a stomping, ungainly way'.
Some blends that have been around for quite a while include brunch (breakfast and lunch), motel (motor hotel), electrocute (electric and execute), smog (smoke and fog) and cheeseburger (cheese and hamburger). These go back to the first half of the twentieth century. Others, such as stagflation (stagnation and inflation), spork (spoon and fork), and carjacking (car and hijacking) arose since the 1970s.
Here are some more recent blends I have run across:
mocktail (mock and cocktail) 'cocktail with no alcohol'
splog (spam and blog) 'fake blog designed to attract hits and raise Google-ranking'
Britpoperati (Britpop and literati) 'those knowledgable about current British pop music'

▪ Analogy 
Analogy substitutes a portion of a term for one related to it, such as “mocktail” for “cocktail.”Sometimes speakers take an existing word as a model and form other words using some of its morphemes as a fixed part, and changing one of them to something new, with an analogically similar meaning. Cheeseburger was formed on the analogy of hamburger, replacing a perceived morpheme ham with cheese. carjack and skyjack  were also formed by analogy.

▪ Acronyms 
Acronyms are formed by taking the initial letters of a phrase and making a word out of it. Acronyms provide a way of turning a phrase into a word. The classical acronym is also pronounced as a word. Scuba was formed from self-contained underwater breathing apparatus. The word snafu was originally WW2 army slang for Situation Normal All Fucked Up. Acronyms were being used more and more by military bureaucrats, and soldiers coined snafu in an apparent parody of this overused device. Sometimes an acronym uses not just the first letter, but the first syllable of a component word, for example radar, RAdio Detection And Ranging and sonar, SOund Navigation and Ranging. Radar forms an analogical model for both sonar  and lidar, a technology that measures distance to a target and and maps its surface by bouncing a laser off it. There is some evidence that lidar was not coined as an acronym, but instead as a blend of light and radar. Based on the word itself, either etymology appears to work, so many speakers assume that lidar is an acronym rather than a blend.
A German example that strings together the initial syllables of the words in the phrase, is Gestapo , from GEheime STAats POlizei 'Sectret State Police'. Another is Stasi, from STAats SIcherheit 'State Security'. Acronyms are a subtype of initialism. Initialisms also include words made from the initial letters of a Phrase but NOT pronounced as a normal word - it is instead pronounced as a string of letters. Organzation names aroften initialisms of his type. Examples:
NOW (National Organization of Women)
US or U.S., USA or U.S.A. (United States)
UN or U.N. (United Nations)
IMF (International Monetary Fund)
Some organizations ARE pronounced as a word:
UNICEF
MADD (Mothers Against Drunk Driving)

▪ Clipping
Clipping is a type of abbreviation of a word in which one part is 'clipped' off the rest, and the remaining word now means essentially the same thing as what the whole word means or meant. For example, the word rifle is a fairly modern clipping of an earlier compound rifle gun, meaning a gun with a rifled barrel. (Rifled means having a spiral groove causing the bullet to spin, and thus making it more accurate.) Another clipping is burger, formed by clipping off the beginning of the word hamburger. (This clipping could only come about once hamburg+er was reanalyzed as ham+burger.)

▪ Derivation
Derivation is the creation of words by modification of a root without the addition of other roots. Often the effect is a change in part of speech.


▪ Affixation (Subtype of Derivation)

The most common type of derivation is the addition of one or more affixes to a root, as in the word derivation itself. This process is called affixation, a term which covers both prefixation and suffixation.

▪ Rhyming compounds (subtype of compounds)
These words are compounded from two rhyming words. Examples:
lovey-dovey
chiller-killer
There are words that are formally very similar to rhyming compounds, but are not quite compounds in English because the second element is not really a word--it is just a nonsense item added to a root word to form a rhyme. Examples:
higgledy-piggledy
tootsie-wootsie
This formation process is associated in English with child talk (and talk addressed to children), technically called hypocoristic language. Examples:
bunnie-wunnie
Henny Penny
snuggly-wuggly
Georgie Porgie
Piggie-Wiggie
Another word type that looks a bit like rhyming compounds comprises words that are formed of two elements that almost match, but differ in their vowels. Again, the second element is typically a nonsense form:
pitter-patter
zigzag
tick-tock
riffraff
flipflop