+0
We can use different words and phrases to highlight a contrast between two parts of a sentence. Some of these words and phrases are:
http://www.bbc.co.uk/learningenglish/course/intermediate/unit-25/tab/grammar
Please explain the use of indefinite article before "contrast". How do I see the countability in its meaning?
If it's countable, you can have more than one of that noun.
+1
JigneshbharatiIf it's countable, you can have more than one of that noun.

Yes.

a contrast
one contrast
two contrasts
some contrasts

+1
JigneshbharatiWe can use different words and phrases to highlight a contrast between two parts of a sentence. Some of these words and phrases are:
although, even though, despite, in spite of, however and but.

One contrast is expressed with the word "although".
Another contrast is expressed with the words "even though".
Another contrast is expressed with the word "despite".
And so on.

All together six contrasts are listed, i.e., six ways of expressing a contrast between two parts of a sentence.

CJ