Yes, it seems to be an alternative, in some situations acceptable, but eccentric and not neutral spelling of this word. It accents the fact that "ea" here are two separate vowels rather than a diphthong: that is the function of the trema (the two dots).
In practice it's not used much, because it's not really necessary: it does not distinguish it from any other word, and trema is not easy to find on English keyboards: so there is no need.
The prepositional phrase for this sentence is "go until Friday." The word "go" is a preposition. Think of it as a squirrel and a log. To find a preposition, say "The squirrel (went) [insert preposition] the log." If it makes sense, it is a preposition. Then just find the phrase to go along with it!
Ok I will help you with that
Faustus uses language that creates images of.<u> A. beauty and desire</u><span>
Select all that apply</span>