1. The subject of Lexicology and the main lexicological problems

native (-er, -ness, -dom) and borrowed (latin: -ant,-ent,-ible,-able; romanic: -age,-ment,-tion; greek: -ist,-ism,-ism).

2. 
   meaning: -er – doer of the action: worker;
   
   • 
     ess – denote gender: lion-lioness;
     
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     -ence/-ance – abstract meaning: importance;
     
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     -dom + -age – collectivity: kingdom.etc.
     
3. 
   Suffixes part of speech they form:
   
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     noun-forming suffixes: -er, -ness, -ment, -th, -hood, -ing.
     
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     Adjective-forming suffixes: -ful, -less, -y, -ish, -en, -ly.
     
   • 
     Verb-forming suffixes: -en (redden, darken)
     

4. Productivity. By productive suffixes we mean the ability of being used to form new occasional or potential words which take part in deriving new words in this particular period of languge development.
The best way to identify productive affixes is to look for them among neologisms. Well most productive suffixes are: noun forming - -er, -ness, -ing, -ism, -ist, -ance, -ancy; adjective forming - -ish, -able, -ion, -edd, -less; adverb forming - -ly; verb forming - -ize, -ise, -ate. By non-productive affixes we mean affixes which are not able to form new words in the period in question. Non-productive affixes are recognized as separate morphemes and posess clear-cut semantic characteristics. ( non-productive suffixes are: noun forming - -hood, -ship, adjective forming - -ful, -some, verb forming - -en. An affix may lose its productivity and then become productive again in the process of word formation. For ex. non-prod. noun forming suffixes –dom, -ship centuries ago were considered as productive. The adjective forming suffix –ish which leaves no doubt to its productivity nowadays has regained it after having been non-prod. for many centuries. The productivity of an affix shouldn’t be confused with its frequency of occurrence. The frequency of occurrence is understood as the existence in the vocabulary of a great number of words containing an affix in question. An affix may occur in hundreds of words but if it isn’t used to form new words it isn’t productive. For ex. adjective forming suffix –ful (beautiful, trustful) is met in hundreds of adjectives but no new words seem to be built with its help. So it’s non-productive.
The logical classification of prefixes. They are characterized according their origin-native and borrowed. 1) be-, mis-(name), un-(selfish), over-(do). 2) latin – pre-, ultra. Greec – anti-, sym. French – en-. Also they classified according their meaning. 1)negative (in, mis, un, non). 2)pr of time and order (after, post, proto) 3)pr of repetitions (re) 4)location (extra, trance, super). 4)size and degree meaning (mega, super, ultra). The main а ща зк is to change the lexical meaning.