by preference

sooner willingly

alternately alternatively as a matter of choice by choice first in lieu of in preference just as soon more readily more willingly much sooner

extremely insignificantly little violently

deliberately freely intentionally spontaneously willingly

at one's discretion by choice of one's own accord on one's own on one's own initiative optionally with all one's heart without being asked without prompting

unintentionally

forced involuntarily obligatory