(8) Concessive sentences, making a Concession or Assumption, granting that, supposing that, although : quamquam, etsī, ŭt although, etc.
Moods in Dependent Sentences.
§ 217. The only moods used in Dependent sentences are the Indicative and the Subjunctive.
When the Subjunctive would be required if the sentence were a Principal one, the Subjunctive must, of course, be used if it is a Dependent one.
If the Indicative would be used if the sentence were a Principal one, the Indicative is retained in a Dependent sentence or changed into the Subjunctive, 'according to the four principles of § 187.
The Mood used often depends on the original meaning of the Conjunction which is used. Thus quamobrem since (lit. on account of which thing) of itself expresses Cause, and so the Subjunctive is not required with it. On the other hand, cum properly means when, and hence, when it is used for since, the idea of Cause has to be expressed by the Subjunctive.
§ 218. Relative Sentences.—In Substantival and Adjectival sentences introduced by a Relative (quī, quālĭs, of which kind, quantŭs how great, etc., quod, the fact that, etc.), the Indicative is used if the Verb states something as a simple independent fact: mĭttĭt ĕum quī vēră nūntĭăt he sends the man who brings true tidings.
But, frstly, if there is any accessory idea of Purpose, Cause, etc., the Subjunctive is required (according to (B), § 187): mīttĭt ĕum quī vēră nūntĭĕt he sends a man who is to bring (or to bring) true tidings.
Secondly, the Subjunctive is required if what is stated is stated as the saying or thought of somebody (according to (C), § 187): dīcĭt ĕt crēdĭt sē ĕum mīttĕrĕ quī vēră nūntĭĕt he says and believes that he sends a man who brings true tidings.
Thirdly, the Subjunctive is usually required (according to (D), § 187) if the Verb which gives the statement
