Why do we use SOLITARY instead of LONESOME or LONELY?

[Alice C.]

Synonym Search, Intermediate level

ESL/EFL Test #114 "Synonyms for solitary and single", question 3

At the end of such a busy day John only wanted to take a ......... walk. He didn't want to see people around for a while.

(a) solitary
(b) lonely
(c) single
(d) lonesome

Synonym Search, Intermediate level

ESL/EFL Test #114 "Synonyms for solitary and single", answer 3

At the end of such a busy day John only wanted to take a solitary walk. He didn't want to see people around for a while.

Correct answer: (a) solitary

Your answer was: incorrect
At the end of such a busy day John only wanted to take a lonesome walk. He didn't want to see people around for a while.
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why do we prefer to use 'solitary' instead of ''lonesome'' or ''lonely''?

Alice

[Mister Micawber]

.
Solitary simply means without anyone else; the solitary person is not necessarily lonesome or lonely; at the moment s/he merely is or wishes to be without a companion. The sentence says that John didn't want to see other people, but a lonely or lonesome person does.
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_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mr. Micawber