1775. Indirect Yes or No questions are introduced by the same
interrogative particles that are used in direct questions (1503). But in
indirect questions, #num# and #-ne# are used without any essential
difference, in the sense of _whether_, _if_. #nōnne# is used thus only
by Cicero, and by him only with #quaerō#: as,
#quaeris num disertus sit?# _Planc._ 62, _do you ask whether he is a
good speaker?_ #quaesīvī cōgnōsceretne sīgnum#, _C._ 3, 10, _I asked if
he recognized the seal_. #quaerō nōnne tibī̆ faciendum idem sit#, _Fin._
3, 13, _I ask whether you ought not to do the same_. #vidēte num
dubitandum vōbīs sit#, _IP._ 19, _consider whether you ought to have any
hesitation_.
1776. The combinations #-ne . . . -ne#, and #an . . . an#, introducing
two separate questions, are rare; #-ne . . . -ne# is mostly confined to
poetry. In a few instances such questions can hardly be distinguished
from alternatives.
1777. A conditional protasis with #sī#, _if_, _to see if_, or #sī
forte#, _if perchance_, sometimes takes the place of an indirect
question in expressions or implications of trial, hope, or expectation:
as, #ībō, vīsam sī domīst#, T. _Hau._ 170, _I’ll go and see if he’s at
home_. Usually with the subjunctive: as, #exspectābam, sī quid
scrīberēs#, _Att._ 16, 2. 4, _I was waiting to see whether you would
write anything_. #circumfunduntur hostēs, sī quem aditum reperīre
possent#, 6, 37, 4, _the enemy came streaming round, to see if they
could find any way of getting in_.