Lewis & Short

ĕnim, conj. [comp. of ĕ for pronom. stem i, and nam], a demonstrative corroborative particle. (Its position is regularly after the first word, or the first two or more closely connected words in the sentence; only in the comic writers sometimes at the beginning. Put after est in the fourth place: in eo est enim illud, Cic. Off. 1, 20, 67: ab omnibus est enim, etc., id. Deiot. 13, 37; al., see below. Put after quoque: id quoque enim traditur, Liv. 2, 18; 3, 50; 23, 12; 27, 22; 30, 1; 33, 30; 36, 27; but not in Cicero, v. Madv. ad Cic. Fin. 2, 33, 108, p. 325.
Sometimes it divides an apparent compound: quotus enim quisque, Tac. Or. 26 fin.)

  1. I. To corroborate a preceding assertion, like equidem, certe, vero; hence freq. connected with these particles, esp. with vero (v. under B.), truly, certainly, to be sure, indeed, in fact: Ch. Te uxor aiebat tua Me vocare. St. Ego enim vocari jussi, certainly, I did order you to be called, Plaut. Cas. 2, 4, 2: ornanda est enim dignitas domo, Cic. Off. 1, 39, 139: in his est enim aliqua obscuritas, in fact, indeed, id. Tusc. 1, 32, 78: ille (Dumnorix) enim revocatus resistere ac se manu defendere coepit, in fact, indeed, Caes. B. G. 5, 7, 8: tum M. Metilius, id enim ferendum esse negat, it was really not to be endured, Liv. 22, 25: enim istaec captio est, this is clearly a trick, Plaut. Ep. 5, 2, 36: enim me nominat, positively he mentions my name, id. Trin. 5, 2, 10: enim non ibis nunc vicissim, nisi scio, you shall positively not go, id. Pers. 2, 2, 54; id. Capt. 3, 4, 60; cf. id. Most. 5, 2, 12: Th. Quid tute tecum? Tr. Nihil enim, nothing truly, Plaut. Most. 3, 1, 24; so, nihil enim, Ter. Ad. 4, 5, 22; id. Hec. 5, 4, 10; cf.: enim nihil, Plaut. Bacch. 4, 4, 51: Pa. Quid metuis? Se. Enim ne nosmet perdiderimus uspiam, id. Mil. 2, 5, 19: tua pol refert enim, id. Stich. 4, 2, 36: certe enim hic nescio quis loquitur, id. Am. 1, 1, 175: certe enim, id. ib. 2, 2, 26; id. As. 3, 3, 24; Ter. And. 3, 2, 23.
    So too in ironical or indignant discourse: tu enim repertu’s Philocratem qui superes veriverbio! you indeed! Plaut. Capt. 3, 4, 36: ex his duo sibi putant concedi: neque enim quisquam repugnat, Cic. Ac. 2, 13, 41 Goer.; cf. id. Mil. 3, 8; id. Deiot. 12, 33 sq.; id. Verr. 2, 1, 13; id. Phil. 7, 8; Liv. 7, 32; 34, 7; Hor. Ep. 1, 19, 44 al.: non assequimur. Isti enim videlicet Attici nostri quod volunt, assequuntur, Cic. Brut. 84, 288; so (with videlicet), id. Font. 9, 19; id. Cat. 2, 6, 12: Ca. Faxo haut tantillum dederis verborum mihi. Me. Nempe enim tu, credo, me imprudentem obrepseris, yes, indeed, I believe you are trying to take me in, Plaut. Trin. 1, 2, 23.
    1. B. Strengthened by vero, and combined with it into one word, ĕnimvēro (unlike enim, usually beginning the sentence), yes indeed, yes truly, of a truth, to be sure, certainly, indeed: enimvero Chremes nimis graviter cruciat adulescentulum, Ter. Heaut. 5, 5, 1: enimvero, inquit Crassus, mirari satis non queo, etc., Cic. de Or. 1, 36; Liv. 5, 25; 1, 51 fin.: postridie mane ab eo postulo, ut, etc.: ille enimvero negat, and of a truth, he denies it, Cic. Verr. 2, 4, 66; so, ille enimvero, id. ib. 2, 5, 39; Liv. 3, 35 fin.: hic enimvero, Cic. Verr. 2, 3, 60: enimvero iste, id. ib. 2, 3, 25.
      In corroborating replies (cf. certe, I. A. 2.): Me. Ain vero? So. Aio enimvero, Plaut. Am. 1, 1, 188; cf. id. Pers. 2, 2, 2: Sy. Eho, quaeso, an tu is es? Ch. Is enim vero sum, id. Trin. 4, 2, 145: Al. Tun’ te abisse hodie hinc negas? Am. Nego enimvero, id. Am. 2, 2, 127; id. As. 3, 3, 98; id. Am. 1, 1, 254: Pa. Incommode hercle. Ch. Immo enimvero infeliciter, Ter. Eun. 2, 3, 37.
      And in ironical or indignant discourse: Da. Ubi voles, arcesse. Si. Bene sane: id enimvero hic nunc abest, that, to be sure, is wanting here as yet, Ter. And. 5, 2, 7; id. Phorm. 3, 1, 1: enimvero ferendum hoc quidem non est, Cic. Verr. 2, 1, 26; Liv. 43, 1; cf. id. 6, 14; 25, 41; 27, 30; 33, 46; 34, 58.
  2. II. Transf.
    1. A. To prove or show the grounds of a preceding assertion, for: haec sunt non nugae; non enim mortualia, Plaut. As. 4, 1, 63: mihi vero omne tempus est ad meos libros vacuum: numquam enim sunt illi occupati, Cic. Rep. 1, 9: quas (geometricas formas) ut vidisset, exclamavisse, ut bono essent animo, videre enim se hominum vestigia, id. ib. 1, 17 et saep.
      In parenthetical sentences: quocirca (dicendum est enim saepius), cum judicaveris, diligere oportet, Cic. Lael. 22, 85; cf. id. Tusc. 2, 24, 58; id. Ac. 2, 7, 22: rumpor et invideo (quid enim non omnia narrem?), etc., Ov. H. 16, 221: di maris et caeli (quid enim nisi vota supersunt?), etc., id. Tr. 1, 2, 1 et saep.
      1. 2. Sometimes the assertion, the reason for which is given, is to be mentally supplied, Cic. Tusc. 5, 9, 26; cf. id. de Or. 2, 6, 24; id. Leg. 2, 7, 17: Am. Qui istuc potis est fieri, quaeso, ut dicis, jam dudum, modo? Al. Quid enim censes? te ut deludam contra? etc., what then do you think? Plaut. Am. 2, 2, 62; cf. Cic. Tusc. 1, 6, 10; Hor. S. 2, 3, 124; Curt. 5, 8; 10, 2 al.
        So the expression: quid enim dicam? commonly ellipt.: quid enim? qs. for what can be objected to the assertion just made? quid enim de T. Tatio Sabino dicam, Liv. 4, 3, 12: quid enim? fortemne possumus dicere eundem illum Torquatum? Cic. Fin. 2, 22, 72; 2, 28, 93; id. Fam. 5, 15, 2; Lucc. ap. Cic. Fam. 5, 14, 2; Hor. S. 1, 1, 7; 2, 3, 132 et saep.
    2. B. To explain a preceding assertion, for instance, namely: Sy. Si futurum est, do tibi operam hanc. Mi. Quomodo? Ut enim, ubi mihi vapulandumst, tu corium sufferas, Plaut. Poen. 4, 2, 33; Sc Metuo maxime. Pa. Quid metuis? Sc. Enim ne nos nosmet perdiderimus, id. Mil. 2, 5, 19: Lu. Di me perdant, si bibi, Si bibere potui. Pa. Qui jam? Lu. Quia enim obsorbui, why because, id. ib. 3, 2, 21; id. Am. 2, 2, 34; id. Capt. 4, 2, 104; id. Cas. 2, 6, 33; Ter. Heaut. 1, 2, 14: quod enim, App. M. 9, p. 228, 16: non igitur videtur nec frumentarius ille Rhodios nec hic aedium venditor celare emptores debuisse. Neque enim id est celare, quicquid reticeas; sed cum, etc., Cic. Off. 3, 13 fin.: antiquissimam sententiam, tum omnium populorum et gentium consensu comprobatam sequor. Duo sunt enim divinandi genera, etc., id. Div. 1, 6, 11; cf. id. de Imp. Pomp. 2, 6. See Hand, Turs. II. p. 374-409.