how come, wherefore, what, how, reason, exactly, anyway, not, actually, because, more...

how, what, when, where, who

motive, reason, cause, more...

part, what, reason, new, see, important, introduction, huge, modern, big, incessant

"why not",   for what,   letter y,   for what reason,   reason to,   how on earth,   for how,   por que,   how could you,   how did