A temporal clause with cum and the Imperfect or Pluperfect Subjunctive describes the circumstances that accompanied or preceded the action of the main verb:— cum essem ōtiōsus in Tusculānō, accēpī tuās litterās (Fam. 9.18.1) , when I was taking my ease in my house at Tusculum , I received your letter. cum servīlī bellō premerētur (Manil. 30) , when she (Italy) was under the load of the Servile War. cum id nūntiātum esset , mātūrat (B. G. 1.7) , when this had been reported, he made (makes) haste. cum ad Cybistra quīnque diēs essem morātus , rēgem Ariobarzānem īnsidiīs līberāvī ; ( Fam. 15.4.6 ), after remaining at Cybistra for five days , I freed King Ariobarzanes from plots. is cum ad mē Lāodicēam vēnisset mēcumque ego eum vellem , repente percussus est atrōcissimīs litterīs ( id . 9.25.3), when he had come to me at Laodicea and I wished him to remain with me, he was suddenly , etc. This construction is very common in narrative, and cum in this use is often called narrative cum . Cum with the Imperfect or Pluperfect Indicative does not (like cum with the Imperfect or Pluperfect Subjunctive) describe the time by its circumstances; it defines the time of the main verb by denoting a coëxistent state of things (Imperfect Indicative) or a result attained when the action of the main verb took place (Pluperfect). Thus the construction is precisely that of postquam etc. (§ 543 . a ). The distinction between the uses defined in §§ 545 , 546, may be illustrated by the following examples: (1) He had a fever when he was in Spain (Shakspere). Here the when -clause defines the time when Cæsar had the fever,—namely, in the year of his Spanish campaign (B.C. 49). In Latin we should use cum with the Imperfect Indicative. (2) Columbus discovered America when he was seeking a new route to India; here the when -clause does not define or date the time of the discovery; it merely describes the circumstances under which America was discovered,—namely, in the course of a voyage undertaken for another purpose. In Latin we should use the Imperfect Subjunctive. The distinction explained in Note 3 is unknown to early Latin. In Plautus quom always has the Indicative unless the Subjunctive is required for some other reason.