Difference between lone, alone and lonely

I have some exercises with these words.

  1. There was only a … traveller sitting in the waiting room.
    a. lone
    b. lonesome
    c. lonely
    d. alone
  2. He … can do the work.
    a. alone
    b. singly
    c. individually
    d. all are correct
  3. The boy has done the work all by his …
    a. lone
    b. lonely
    c. lonesome
    d. alone
    Please help me with these exercises. And I also want to know the uses of each word so that I can gain more experiences.
    Thanks a lot.

Hi, Sophie

I can answer your third question: the answer is “lonesome”.
There’s an idiom all by one’s lonesome which means by oneself, which you have to learn.
Take a look at this reference: answers.com/topic/alone