1) The classification according to the part of speech.

Noun-forming suffixes	-age	bondage, breakage, mileage
	-ance-ence	assistance, reference
	-ant-ent	student, defendant
	-dom	kingdom, freedom
	-ee	employee, interviewee
	-eer	profiteer
	er	writer, speaker
	-ess	actress, lioness
	-hood	manhood, brotherhood
	-ing	building, meaning, washing
	-ion-sion-tion-ation	rebellion, creation, tension, explanation
	-ism-icism	heroism, criticism
	-ist	novelist, communist
	-ment	government, nourishment
	-ness	tenderness, clevernees
	-ship	friendship
Adjective-forming suffixes:	-able – ible -uble	unbearable, audible, soluble
	-al	formal
	-ic	poetic
	-ical	ethical
	-ant-ent	repentant, dependent
	-ary	revolutionary
	-ate - ete	accurate, complete
	-ful	delightful
	-ian	African, Australian
	-ish	Irish, reddish, childish
	-ive	active
	-less	useless
	-like	lifelike
	-ly	manly
	–ous-ious	tremendous, curious
	-some	tiresome
	-y	cloudy
Numeral-forming suffixes	-fold	twofold
	-teen	sixteen
	-th	seventh
	-ty	sixty
Verb-forming suffixes	-ate	facilitate
	-er	glimmer
	-en	shorten
	-fy-ify	terrify, speechify
	-ize-ise	recognize, realise
	-ish	establish
Adverb-forming suffixes:	-ly	coldly
	-ward-wards	upward, northwards
	-wise	likewise

2) according to lexico-grammatical character of the stem.

added to verbal stems	er, ing, able, ment	commuter,suffering, readable, involvment
added to noun stems	less, ful, ish	Powerless, powerful, childish
added to adjective stems	en, ness.	weaken, clannishness

3) semantic classification.

It is quite relative, but there are 8 main groups:

the agent of the action	er (teacher, worker, manager), ist (taxist), ent (student)
nationality	–ian(Russian, Canadian), ese (Japanese), ish (English)
collectivity	-ry (gentry, peasantry
dimininituveness	ie(horsie), let (booklet), ling(duckling), -ette (kitchenette, launderette, lecturette, maisonette)
quality	- ity (readability
feminine gender	ess(actress), ine(heroine
abstract notions	–hood(childhood), ness (politeness), ence\ance(tolerance)
derogatory	-ard(drankard), ster(gangster)

Classification of prefixes

Both the simple word and its prefixed derivative mostly belong to the same part of speech: e.g. the prefix mis-when added to verbs, conveys the meaning 'wrongly', 'badly', behave - misbehave, pronounce - mispronounce. There may be other cases where the semantic rela­tionship is slightly different but the general lexico-grammatical meaning remains: giving - misgiving

To some extent the semantic effect of a prefix may be called adverbial because it modifies the idea of manner, time, place, degree and so on.

The prefixes pre- and post- refer to time. E.g. historic - prehisto­ric, pay - prepray, view - preview.

The prefixes in, a,ab- modify the root for place: e.g. income, abduct.

Several prefixes serve to modify the meaning of the stem for degree. The examples are out, over-and under-.

The prefix out- means 'in a manner that surpasses': outlive - “to live longer”, outnumber – “to exceed in number”.

The group of negative prefixes is so numerous that some scholars even find it convenient to classify prefixes into negative and non-negative ones. They are: de-, dis-, in-,im,-il-, ir-, un.

The prefix de-occurs in many neologisms, such decentralize, deconta­minate etc.

The general idea of negation is expressed by dis: Agree - disagree 'not to agree', appear - disappear (disappear is the reverse of appear).

Non- is often used in abstract verbal nouns such as noninterference or nonresistance.

The most frequent by far is the prefix un; it may convey two different meanings.

1) Simple negation, when attached to adjective stems or to participles: happy-unhappy. It is immaterial whether the stem is native or borrowed, as the suffix un- readily combines with both groups. 2) The meaning is different when un- is used with verbal stems. In that case it shows action contrary to that of the simple word: bind - unbind, do – undo.

A very frequent prefix with a great combining power is re. It denotes repetition of the action expressed by the stem, e.g. to rearrange, to recast.

The majority of prefixes affect only the lexical meaning of words but there are some important cases where prefixes serve to form words belon­ging to different parts of speech as compared with the original word.

These are in the first place the verb-forming prefixes be- and en. Be- forms transitive verbs with adjective and noun stems and changes intransitive verbs into transitive ones,e.g. to belittle – “to make little”; to benumb – “to make numb”;.

The prefix en-em- is used to form verbs from noun stems with the meaning “put (the object) into”, or on e.g. to embed, to encamp and to form verbs with adjective and noun stems with the meaning “to bring into such condition or state”, as in to enable , to enslave. The prefix a- is the characteristic feature of the words belonging to statives: aboard, afraid, asleep, awake, etc.

The prefixes pre; post-, non-, anti- and some other Romanic and Greek prefixes very productive in present-day English serve to form adjec­tives retaining at the same time a very clearcut lexical meaning, e.g. anti-war, pre-war, post-war, non-party, etc.

The valency of affixes and stems

The combining power or valency of affixes is the possibility to occur with certain types of stems. E.g. unhappy, untrue and unattractive are quite regu­lar combinations, while unsad, unfalse, unpretty seem unusual. The possibility of a particular stem taking a particular affix depends on phonomorphological, morphological and semantic fac­tors. The suffix -ance -ence, for instance, occurs only after b, t: disturbance, insistence. but not after s or z: condensation, organization.

The combining possibilities (or valency) are very important semantically because the meaning of the derivative depends not only on the morphemes of which it is composed but also on combinations of stems and affixes that can be contrasted with it. Contrast is to be looked for in the use of the same morpheme in different environment and also in the use of different morphemes in environments otherwise the same: e.g. the difference between the suffixes -ity and –ism becomes clear if we compare them as combined with identical stems in the following oppositions: humanity- humanism; reality - realism. The words with -ity mean the quality of being what the corresponding adjective describes, or an instance of this quality. Such nouns are countable. The suffix -ism forms nouns naming a disposition to what the adjective describes, or a corresponding type of ideology. Being uncountable they belong to a different lexico-grammatical class.