Example : He was alone when we met him.
She is alone much of the time.
The lone skier on the mountain.
A lonely fisherman stood on a tuft of gravel.
A lonely soul.
A solitary traveler.

Synonyms : alone, lonely, solitary

Example : A lone wolf.
A lonely existence.
A man of a solitary disposition.
A solitary walk.

Synonyms : lonely, solitary

Example : The lone doctor in the entire county.
A lonesome pine.
An only child.
The sole heir.
The sole example.
A solitary instance of cowardice.
A solitary speck in the sky.

Synonyms : lonesome, only, sole, solitary