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

Examples:

• 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.

4.  Concession

Conjunctions under the heading of Concession are: although, even if, though, whether … or, while, as

Examples:

• 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.