The frogs shall come up comes at the end of the sentence in the Hebrew, in order to give emphasis to on you and on your people and on all your servants. Come up on really means to “jump up on” (Good News Translation). Your is singular in each case. Note the quotation marks in Revised Standard Version, which indicate the end of a quote within a quote within a quote.

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .