Here are the major branches of linguistics

Task 1.
MODULARITY
Although different languages use different sets of sounds, their sounds are organized and combined according to just a few principles.
Most linguistics believe that language is a modular system. That is, people produce and interpret language using a set of component subsystems in a coordinated way.

DISCRETENESS

The range of sounds that human beings can make is continuous, like a slide whistle. For example, you can slide from a high “long e” sound (as in feed) all the way down to a low “short a” sound (as in bat) and then slide back to a “long o” sound (as in poke) – all in one continuous glide.

ARBITRARINESS

Arbitrariness in human language refers to the fact that the meaning of linguistic signs is not predictable from its word form, nor is the word form dictated by its meaning/function.


Task 2.
LEXICOLOGY
Lexicology is the scientific investigation of lexicon of the language, including, for example, its historical development, its social stratification, its quantitative composition, or the way in which some thematic area is encoded.
Here are the major branches of linguistics:

• 
  Phonology: The sounds in a speech in cognitive terms.
  
• 
  Phonetics: The study of sounds in a speech in physical terms.
  
• 
  Syntax: The study of the formation and structure of sentences.
  
• 
  Semantics: The study of meanings.
  
• 
  Morphology: The study of the formation of words.
  

Main branches of lexicology

1) Semasiology or semantics, including the semantic classification of English words;
2) The study of word-structure and word-formation;
3) The study of word-equivalents, or idioms and phraseological units;
4) A brief etymological survey of the English word-stock;
5) Fundamentals of English lexicography.


Task 3

Lexicology is the branch of linguistics that analyzes the lexicon of a specific language. A word is the smallest meaningful unit of a language that can stand on its own, and is made up of small components called morphemes and even smaller elements known as phonemes, or distinguishing sounds.

1. 
   Lexicology: central terms
   
2. 
   Parts and areas of lexicology
   
3. 
   Two approacges to languag study
   
4. 
   Lexical units
   
5. 
   Varieties of words.
   

The term lexicology derives from the Greek word lexicon (neuter of lexikos, "of or for words", from lexis, "speech" or "word") and -logia, "the study of" (a suffix derived from logos, amongst others meaning "learning, reasoning, explanation, subject-matter").