Originally Answered: Need phrase translated into old english?
Old English is that written and spoken before the Norman Conquest, which is as different from contemporary English as Danish is from Old Norse, or Romanian from Latin. I presume you really mean "Early Modern English", a compromise dialect invented by our first printer in the late 15th century as a commercial device to give his books the widest possible market. You could start by changing "you" to "ye", the nominative form which persisted until about 1550 and was revived as a conscious archaism by the translators of the King James Bible and by Victorian hymn writers. "So" is OK, but you could consider "thus" as a more formal, and therefore more old-fashioned alternative. "May" in the plural was a Caxtonian innovation: earlier English (e.g. Geoffrey Chaucher's) would have added the ending -en after the plural subject "ye". That would turn your phrase into "Thus mayen ye all." Despite their use in German, I have never quite understood the difference between weak adjectives (such as "all") and their strong counterparts (in this case, "alle") which survived in English into Chaucer's time, but I strongly suspect he would have used "alle". Does "thus mayen ye alle" strike you as antiquated enough?" If not, you could replace the "th" with a thorn, the Icelandic letter that English replaced with "th" from fear of confusion with "y"--whence "Ye olde tea shoppe".
PS Beowulf's English would have had a "g" for the "y" of "may", making the whole phrase something like
Yus maggen ye alle, where the first Y represents a thorn that I do not know how to type..