I promised you a bit of clarification of the first sentence in the excerpt from Egeria. I will say right away that I'm mostly interested in you being able to translate this sentence accurately and I don't really expect you to be able to explain everything as I am going to do.
So, a translation first:
In order that your affection might know what divine service is practised/
performed on each day, every day, in those holy places, I am obliged to
inform you (facere certos), being aware that you would gladly know those
things.
A lot depends on the tense of debui. It is possible that Egeria is thinking of the common use of debitum and so using a present perfect here ("I have come to be obliged/I have incurred the obligation"). More probably, she is copying the common Latin use of the perfect as an epistolary tense (A&G 479). That is, the tenses of the verbs used reflect the perspective of the reader: when the reader reads this, Egeria will have been, in the past, obliged....
Since debui is perfect, the verbs that depend on it (in dependent subjunctive clauses) must follow the general sequence of tenses.
sciret: subj. in purpose clause (ut …), imperfect because of sequence of tenses (i.e., main verb is perfect; so the imperfect is used to indicate incomplete action; A&G 482 ff., for here see esp. 484).
habeatur: subj. in indirect question (implied after sciret:
sciret … quae …). It is present tense because it is a general statement. (sequence of tenses
doesn’t apply here).
haberetis … cognoscere: (see G.4 (c)): habeo + inf. = future;
here haberetis is impf. subj., subj. because of an implied conditional sense (“would
be…”), imperfect because it is still ultimately governed by debui (tense also caught by “would”—as
in “he would go to the store every day” [imperfect]), sciens being a participal
that takes its tense from is relationship to the main verb, debui. “Habetis
cognoscere” would be the simple future, this use of the imperfect haberetur indicates
the future from the perspective of the past (hence Sidwell’s “you would be glad to know”).
But if I were to ask you any questions on an exam about these verbs they would be restricted to:
1. parse sciret and identify what type of clause it is in (3s impf. subj. act.; purpose clause);
2. parse habeatur and explain its mood (3s pres. subj. pass.; indirect question); and
3. explain the presence of the verb habeo in haberetis cognoscere (it, in effect, forms a future).
As an aside, for the phrase affectio uestra, see Part 1, 5.7 sed cum
leget affectio vestra libros sanctos Moysi...; 7.3 Nam mihi
credat volo affectio vestra...; 12.2 Nam
mihi credit volo affection vestra...; 20.13 Nam
nolo aestimet affectio vestra...; 22.10 10. De
quo loco, dominae, lumen meum, cum haec ad vestram affectionem darem...
You may go take an analgesic now.
