Language Structure: language is a “nested structure.” For example: letters are combined to form syllables, syllables are combined to form words, words are combined to form clauses and sentences. (Hawkins, 177) 

Human language involves two types of structures. In the first, elements from a finite set of meaningless “sounds” are combined into meaningful “words” and parts of words, known as “morphemes.” Linguists call this “phonology.” The rules of phonology cover “intonation“ and “rhythm,” as well as the way specific sounds can be combined. In the second type of structure, words and morphemes are combined into “phrases.” This is what linguists call “syntax.” (Kenneally, 154) (Includes) factors involved in carrying out a structural analysis of language, whether spoken, written or signed. The main levels that linguists have proposed in order to elucidate the way languages operate. (Crystal, 81)

Context: physical or psychological environment in which communication occurs. (Floyd, G2) The various elements of the experience, questions asked, and setting. (Johnson, 315) The linguistic environment of an element. The non-linguistic situation in which language is used. (Crystal, 424) Adjective - 'contextual.'

Parts of Speech: each of the several categories to which words are assigned in accordance with their grammatical and “semantic” functions. (Oxford)

Adjective: a word designating an attribute and added to a noun, to describe the thing more fully. (Oxford)

Adverb: a word that qualifies or modifies another, especially an adjective, a verb, or another adverb, so as to express a relation of place, time, circumstance, manner, cause, degree, etc. (Oxford)

Article: a member of a small set of words that give definiteness or indefiniteness and specificness or genericness to the application of a noun. (Oxford)

Conjunction: a word used to connect clauses or sentences or to coordinate words in the same clause. (Oxford)

Exclamation: a sudden impassioned or emphatic utterance, a cry. (Oxford)

Interjection: the utterance of an exclamation expressing emotion. (Oxford)

Noun: a word used as the name or designation of a person, place, or thing. (Oxford)

Preposition: a word governing and usually preceding a noun,  pronoun, etc., and expressing a relation between it and another word. (Oxford) 

Relational Words: a word expressing relation between other words. (Oxford)

Verb: a word used to indicate the occurrence of or performance of an action or the existence of a state or condition. (Oxford)

Sentence: the largest structural unit that displays ... grammatical relationships, not dependent on any other structure. (Crystal, 436) A series of words complete in itself as the expression of a thought, containing or implying a “subject” and “predicate,” and conveying a “statement,” “question,”  exclamation, or command. (Oxford)

Clause: a simple sentence; a distinct part of a sentence including a subject and predicate, or one resembling this; a single passage of discourse or writing. (Oxford) A structural unit smaller than the sentence, but larger than phrases or words. (Crystal, 423)

Phrase: a small group of words expressing a single concept or entering with some degree of unity into the structure of a sentence. Does not contain a predicate or ‘finite verb.’ Any 'syntactic' unit larger than a word and smaller than a sentence. Also, a characteristic or “idiomatic” expression. (Oxford) A group of words smaller than a clause, forming a grammatical unit. (Crystal, 434)

Predicate: the part of a sentence or clause containing what is said about a subject. (Oxford) The clause element that gives information about the subject. (Crystal, 434) The assertion of something about a subject. (Oxford) Noun - ‘predication.’

Question: a sentence worded or expressed in a form such as to elicit information from a person; inquiry. (Oxford) A ‘question of fact’ addresses whether something is true or not. A ‘question of policy’ addresses the best course of action or the best solution to a problem. A ‘question of value’ addresses the merit or morality of an object, action, or belief. (Griffin, 447)

Subject: a noun or noun equivalent about which a sentence is predicated and especially with which the verb agrees. (Oxford) The clause about which something is stated. (Crystal, 438)

Statement: the action or an act of stating, alleging, or enunciating something. A thing that is stated; an allegation, a declaration; specifically a verbal expression whose content is assessable in terms of truth or validity. (Oxford)

Symbol System: a culturally contrived system of meaning that captures and conveys important forms of information. Language, picturing, and mathematics are but three nearly worldwide symbol systems that are necessary for human survival and productivity. Musical notation provides an accessible and versatile symbol system. (Gardner, 8-9)

Alphabet: a set of letters used in writing a language; as a set of “symbols” or signs used for these letters. (Oxford) A writing system in which a set of symbols represents the "phonemes" of a language. (Crystal, 421)

Symbol: a representation of an idea. (Floyd, G6) Items used to represent other things, ideas, or events. For example, the letters of the alphabet are symbols for specific sounds in English. (McCornack, 182) It is possible to talk about writing systems on the basis of the size, style, and configuration of the symbols, or the direction in which they are written. (Crystal, 198) A word or phrase spoken by a speaker. (Griffin, 448) (Also), an abstract, arbitrary, and ambiguous representation of a phenomenon. (Wood, 336)

Word: any of the sequences of one or more sounds or morphemes (intuitively recognized by native speakers as) constituting the basic units of meaningful speech used in forming a sentence or sentences in a language. (Oxford) Usually the easiest units to identify, in the written language. In most writing systems, they are the entities that have spaces on either side. (Crystal, 91)

Affix: a grammatical element prefixed, infixed, or suffixed to the root of a word. (Oxford)

Affixation: addition of an affix. (Oxford)

Infix: an affix inserted into a word. (Oxford)

Morpheme: the smallest contrastive unit of grammar. (Crystal, 432) The smallest “morphological” unit of language, which cannot be analyzed into smaller units. (Oxford)

Phonemes: the basic speech sounds of a language. (Coon, 337) The smallest contrastive unit in the sound system of a language. (Crystal, 434)

Prefix: an element placed at the beginning of a word to adjust or qualify its meaning or in some languages as an “inflection.” (Oxford)

Suffix: an element placed at the end of a word to form a derivative or as an inflection. (Oxford)

Syllable: a unit of pronunciation uttered without interruption, forming the whole or part of a word and comprising a sound. Also, a symbol, character, or set of characters, representing a corresponding element of written language. (Oxford) An important abstract unit in explaining the way vowels and consonants are organized within a sound system. (Crystal, 166)