Salvete omnes!
Quick question.
Which pair of sentences are correct:
Nescio ubi sum. Nescio quis sum.
Or:
Nescio ubi sim. Nescio quis sim.
In otherwords, is it the indicative or the subjunctive that must be used here. I never learned that a subjunctive is used after ubi. As for quis: isn’t that what’s known as a relative clause of purpose? What kind of clause would be in the first sentence in which I use ubi?
Indirect questions normally take the subjunctive.
Deus meus! (is that the correct way to say my God?)
You’re right. I had forgotten about indirect questions! And I was just reading about them last night. My mind got so tangled up on relative clauses of purposes this monring that I forgot. So for the record, they’re not relative clauses of purpose, right? If not (which they’re probably not) what would be an example of such?
A Roman would likely say “Mehercule!” No, indirect questions are not relative clauses of purpose. They are indirect questions… 
Relative clauses of purpose look more like this: Caesar nuntios misit qui mandata sua nuntiarent, “Caesar sent messengers to announce his instructions,” lit., “who were to announce his instructions…”
I’ll let A&G explain it:
- Relative Clauses of Purpose are introduced by the relative pronoun qui or a relative adverb (ubi, unde, quō, etc.). The antecedent is expressed or implied in the main clause:—
mittitur L. Dēcidius Saxa quī locī nātūram perspiciat (B. C. i. 66), Lucius Decidius Saxa is sent to examine the ground (who should examine, etc.).
scrībēbat ōrātiōnēs quās aliī dīcerent (Brut. 206), he wrote speeches for other men to deliver.
eō exstīnctō fore unde discerem nēminem (Cat. M. 12), that when he was dead there would be nobody from whom (whence) I could learn.
huic nē ubi cōnsisteret quidem contrā tē locum relīquistī (Quinct. 73), you have lift him no ground even to make a stand against you.
habēbam quō cōnfugerem (Fam. iv. 6. 2), I had [a retreat] whither I might flee.NOTE.—In this construction quī = ut is (etc.), ubi = ut ibi, and so on (§ 537. 2).
Allen, J. H., & Greenough, J. B. (1903). Allen and Greenough’s New Latin Grammar. (J. B. Greenough, G. L. Kittredge, A. A. Howard, & B. L. D’Ooge, Eds.) (p. 341). Boston: Ginn & Co.
It’s funny that you quote A&G. I was reading that part too from my copy last night.
Gratias tibi ago, Barry (how would you say Barry in Latin? Barrius? So would the vocative be Barrie? Just a wild guess. I’m probably wrong)
I’ve alway gone with Barrius. But second declension nouns whose nominative ends in -ius usually just use -ī for the vocative, so Barrī. There is a funny story about this in Aulus Gellius, however, two Roman grammarians arguing about the correct vocative…