þancie ic Þe, for þam Þu mid me bist. Word for word: Thank I you, because you with me are

With the "for þam" being a subordination conjunction, this sentence becomes one of two clauses, one principle (ie it can stand alone as its own sentence) and one subordinate (it modifies and gives context to the principle). These can be in either order, but the word order within each clause is more or less crucial.

A principle typically takes the form verb before subject, either immediately or with some other words in between. With "þancie" (first person present indicative verb) first, the subject "ic" (I) must come later. "þe" is you, inflected in the accusative, as it is the object. This is where old English word order is more lax than modern. "Ic Þe þancie" is equally correct.

The subordinate clause must begin with that type of conjunction. In this case that's "for þam" (for, because). An optional "Þe" may be added straight after to make it extra clear you mean this as a subordination conjunction and not a simple adverb (which would take a meaning more like "therefore"). That's unnecessary here because of the word order (all those þ words are a tongue twister otherwise!) The word order of a subordinate clause must be subject next, before any verbs. This is "þu" (you, again, now in the nominative as it's the subject of this clause not the object). I've chosen to have the verb "bist" (are, as the second person present indicative) at the very end of the sentence. Before this is the "mid me" (with me, me taking the dative case).