i Register
In some senses, whatsoever is marked as formal, literary, archaic. Watch for register when choosing this word.
det
Whatever.
The building may be used for whatsoever purpose the tenant desires.
[…]In whatſoever ſhape he lurk,[…]
adv
In any way; at all; whatever.
He gave me no answer whatsoever.
In the old days, to my commonplace and unobserving mind, he gave no evidences of genius whatsoever. He never read me any of his manuscripts, […], and therefore my lack of detection of his promise may in some degree be pardoned.
pron
Whatever.
Whatsoever you seek, you will find.
Whatsoever God hath said unto thee, do.