The 3rd and 4th headings on Conjunctions are Cause or Reason and Concession:-
3. Cause or Reason
Conjunctions under the heading of Cause or Reason are: as, because, lest, since
- As it was raining heavily I did not go for my morning walk.
- The television was tuned loud because my mother is a bit deaf.
- He was nervous lest he should fail the test.
- I am not calling since he has promised to call back.
Conjunctions under the heading of Concession are: although, even if, though, whether … or, while, as
- Although I have explained in detail, he still does not understand.
- He would not betray his friend even if you put on the pressure.
- Though the doctors have made all the tests they could not ascertain her sickness.
- I am telling you the truth whether you believe it or not.
- While I was cycling around I saw some beautiful rare birds.
- Stubborn as he was, he relented.