A clause is a key grammatical structure and this means that clauses are things that you need to have, at the very least, a basic grasp of. Thought of at its simplest, a clause can be considered as a short 'sentence' - one that occurs either on its own (e.g. "I ate the jelly") or together with other clauses to make a longer sentence (e.g. "because I was hungry").
A clause can be what is called independent. This mean it is acting as a simple sentence, as in the example, "I ate the jelly". Independent clauses can also exist as a part of a larger sentence when they are called not an "independent clause" but a main clause.
Another common type of clause exists just to help out the meaning of a main clause. This second kind of clause is, therefore, dependent on its main clause for its meaning. An example would be the dependent clause, "because I was hungry"; you'll see here that there is an extra word at the start of the clause: "because". It is this extra word that stops the clause being able to be independent or to be a main clause; the word "because" forces the clause to be dependent on some other main clause, e.g. "I ate the jelly because I was hungry". This words acts to subordinate its clause and so is called a subordinator. Subordinators create dependent clauses - more often, these days, called subordinate clauses (sometimes reduced to "sub-clauses"). There are many subordinators.
Look at this example: "He hit him even though he was a friend":
He hit him MAIN CLAUSE
An important kind of clause acts as if it were an adjective - it adds extra information about a noun or noun phrase. These clauses are called relative or adjectival clauses. They can seem confusing because they can be inserted in between their main clause, e.g. "The girl who wore a red dress left early." This sentence contains one main clause "The girl left early"
The structure of clauses is fairly fixed in English syntax
S+V+O: Alison / sang / a song.
Many patterns of words exhibit a quality known as cohesion. This means that they form coherent units. Phrases are an important coherent grammatical unit. Words that cohere are cohesive: they appear to act not as individual words but as a single unit, e.g. 'inside out', 'at three o'clock', 'the awful creature', 'has been eating', 'in a traditional manner'. These examples of coherent groups are all phrases, but clauses, sentences and discourses are also, if they are to be effective in communicating ideas and facts, coherent.
At the level of discourse, the reader or listener also needs to be able to link the different sentences and paragraphs (or stanzas in a poem, etc) in a logical way. This is achieved by many linguistic means including graphology, semantics, pragmatics, narrative structure, tone, lists, pronouns, proper nouns, repetition of either logical or similar ideas, use of synonyms, and so on. The analysis of the cohesive qualities (i.e. the coherence) of a text is the analysis of discourse structure.
The denotation of a word is its direct, literal or specific meaning (as can be found in a dictionary). If a word also has implied or associated meanings when used in a certain way, these are called the word's connotations. The word 'bat' in this sentence is being used with its denotation: 'A bat is a flying mammal.' however, the word, 'bat' can also take on extra meanings, often metaphorical, e.g. 'He went like a bat out of hell'.
Interestingly, the word 'bat' also happens to have several possible denotations: 'a cricket bat', 'a vampire bat', 'They bat next' (as well as other slang and dialect meanings): words that have several denotations are called polysemic. Polysemy is an area of semantics and pragmatics.
The content is the meaning contained by a word, phrase, clause or sentence and this is involved with its function. The separation of form, function and content is a theoretical way of discussing the effect of each even though all three are inextricably linked.
Context is always an important aspect to consider whenever you analyse a text. Context refers to those particular elements of a situation that in some way or another affect the text (for example, the effects of time, place, ideology, social hierarchies, relationships, etc.).
Importantly, language has two potentially important contextual aspects: the context in which it was created and that in which it was interpreted. For example, a letter from a manager to one of his staff will be affected by context such as the situation itself, the power relationship that exists between the manager and the worker, the historical conditions and so on. Another example, when you speak to your parents or when you speak to a friend on the phone you will see that context naturally affects the linguistic choices - the style - of the discourse in important ways. Also see register.