なければならない/なくてはならない/なければいけない/なくてはいけない/なければだめ/なくてはだめ => must N5
を[余儀「よぎ」]なくされる => Must do A N1
Will, Decision, Doing
~かいもなく/~がいもなく      => despite; even though ~. I tried hard / hard but unfortunately ~ N1
~べくもない      => cannot possibly be ~. N1
かいもなく => Even though A, N2
Contrast,Surprise
なくてもいい => Don't have to A N4
Can, Should, Must
~といえなくもない => It can be said that ~ N1
Concession
いくらも…ない => there is only a few/ little… N3
More or less in quantity
... なくもない => it's not that; I may (double negative) N2
Trend
なくともよい => don't need to do something ... N2
Necessity, obligation
ろくでもない => good-for-nothing, useless, worthless N1
Evaluate
[命令「めいれい」] => Do A (command) N4
Can, Should, Must