English as she is spoke.

You may remember the joke about the brute who "raped Thrace thrice" - but did you realise that thrice is the end of the line?  Once, twice, thrice - and that's it.  There is no single word for four times, five times and so on.  Why not?  Who knows.  Perhaps the question is more - why do we have special words for one time, two times and three times.  Other languages tend not to.  French goes une fois, deux fois, trois fois and so on.  German has einmal, zweimal, dreimal etc.  So it's English which, as is so often the case, is unusual.