Language analysis terms

Hi,

I am having a hard time understanding what is meant by:

concept/meaning
function
appropriacy/use

What are the key words that I need to use to find out how to use them.

I know that sometimes appropriacy means whether the use is formal or informal. What are the othe rpossibilities?

Is the function of a word or phrase that of a request/advice/comman, etc. Are there any others?

Concept/meaning ????

Does it overlap with function? Are they similar?
For example: The word despite + present participle

Is the concept of despite that of contrast? What is its function? Is it also contrast or unexpected result/surprise?

Must all of these terms be used at all times when analyzing a structure?

Can you please clarify the above for me? Thank you.
Ali

Functions- there are many: obligation, necessity. Functional teaching groups words and phrases into categories of what they do, not their grammar.

Appropriacy- simply ask whether the language fits the context. That'll tell you it's appropriacy. Formal/semi-formal/informal are broad groups, but that doesn't necessarily mean that anything can be rigidly labelled this way.

Despite + *gerund* - the concept hiding behind it is to show a contrast, but its function could be to show the speaker's surprise.

;-)