The 4 groups are clearly (!) intended to be resolved as follows:
Group 1
AWAY, VERSION, ENDS, QUANDARY
These are one-word titles of poems in Robert Frost's 1962 collection, In the Clearing.
Group 2
NIGHT, SLEEP, DEATH, STARS
These words all appear in the last line of Walt Whitman's short poem, A Clear Midnight:
This is thy hour O Soul, thy free flight into the wordless,
Away from books, away from art, the day erased, the lesson done,
Thee fully forth emerging, silent, gazing, pondering the themes thou lovest best,
Night, sleep, death and the stars.
Group 3
MEMORIES, SOLDIERS, THOUGHTS, KNOWLEDGE
Four words which follow 'no' in the Wallace Stevens poem, A Clear Day and No Memories:
No soldiers in the scenery,
No thoughts of people now dead,
As they were fifty years ago,
Young and living in a live air,
Young and walking in the sunshine,
Bending in blue dresses to touch something,
Today the mind is not part of the weather.
Today the air is clear of everything.
It has no knowledge except of nothingness
And it flows over us without meanings,
As if none of us had ever been here before
And are not now: in this shallow spectacle,
This invisible activity, this sense.
NB 'No Memories' appears in the title!
Group 4
DESCRIES, WAKES, SINGS, BRINGS
Four verbs which appear in the Robert Louis Stevenson poem, The Cock's Clear Voice Into the Clear Air:
Line 6: The coming morn descries,
Line 7: And, mankind's bugler, wakes
Line 9: He sings the morn upon the westward hills
Line 11: He sings it in the land
Line 13: He brings to me dear voices of the past,
And in case it isn't clear by now, all four groups are connected by:
the appearance of the word 'CLEAR' within a poem, its title or its collection!