Allen and Greenough's New Latin Grammar for Schools and Colleges
J. B. Greenough, G. L. Kittredge, A. A. Howard, Benj. L. D'Ooge, Ed.

[*] a. Prepositions are often prefixed to Verbs. In these compounds the prepositions retain their original adverbial sense:—

1. ā, ab , AWAY: ā-mittere, to send away.
2. ad, TO, TOWARDS: af-ferre ( ad-ferō ), to bring.
3. ante , BEFORE: ante-ferre, to prefer; ante-cellere, to excel.
4. circum , AROUND: circum-mūnīre, to fortify completely.
5. com-, con- ( cum ), TOGETHER or FORCIBLY: cōn-ferre, to bring together; collocāre, to set firm.
6. dē , DOWN, UTTERLY: dē-spicere, despise; dē-struere, destroy.
7. ē, ex, OUT: ef-ferre ( ec-ferō ), to carry forth, uplift.
8. in (with verbs), IN, ON, AGAINST: īn-ferre, to bear against.
9. inter , BETWEEN, TO PIECES: inter-rumpere, to interrupt.
10. ob , TOWARDS, TO MEET: of-ferre, to offer; ob-venīre, to meet.
11. sub , UNDER, UP FROM UNDER: sub-struere, to build beneath; sub-dūcere, to lead up
12. super, UPON, OVER AND ABOVE: super-fluere, to overflow.

[*] Note 1.--In such compounds, however, the prepositions sometimes have their crdinary force as prepositions, especially ad , in, circum , trāns , and govern the case of a noun: as, trānsīre flūmen, to cross a river (see § 388. b).

[*] Note 2.--Short a of the root is weakened to i before one consonant, to e before two: as, faciō , cōnficiō , cōnfectus; iaciō, ēiciō , ēiectus . But long a is retained: as, perāctus .

[*] b. VERBS are also compounded with the following inseparable particles, which do not appear as prepositions in Latin:—

1. amb- (am-, an-), AROUND: amb-īre, to go about (cf. ἀμφί, about).
2. dis-, dī-, ASUNDER, APART: dis-cēdere, to depart (cf. duo, two); dī-vidĕre, to divide.
3. por-, FORWARD: por-tendere, to hold forth, predict (cf. porrō, forth).
4. red-, re-, BACK, AGAIN: red-īre, to return; re-clūdere, to open (from claudō, shut); re-ficere, to repair (make again).
5. sēd-, sē-, APART: sē-cernō, to separate; cf. sēd-itiō, a going apart, secession ( eō , īre, to go).

[*] c. Many Verbals are found compounded with a preposition, like the verbs to which they correspond:—

1. per-fuga, deserter; cf. per-fugiō.
2. trā-dux, vine-branch; cf. trā-dūcō ( trāns-dūcō ).
3. ad-vena, stranger; cf. ad-veniō.
4. con-iux ( con-iūnx ), spouse; cf. con-iungō.
5. in-dex, pointer out; cf. in-dīcō.
6. prae-ses, guardian; cf. prae-sideō.
7. com-bibō, boon companion; cf. com-bibō, -ĕre.

[*] d. An Adjective is sometimes modified by an adverbial prefix.

1. Of these, per- (less commonly prae-), very; sub-, somewhat; in-, not, ar regular, and are very freely prefixed to adjectives:—

   [*] Note.-- Per and sub , in these senses, are also prefixed to verbs: as, per-terreō, terrify; sub-rīdeō, smile. In īgnōscō, pardon, in- appears to be the negative prefix.

   per-māgnus, very large.	in-nocuus, harmless.
   per-paucī, very few.	in-imīcus, unfriendly.
   sub-rūsticus, rather clownish.	īn-sānus, insane.
   sub-fuscus, darkish.	īn-fīnītus, boundless.
   prae-longus, very long.	im-pūrus, impure.

The negative in- sometimes appears in combination with an adjective that does not occur alone:—
1. in-ermis, unarmed (cf. arma, arms).
2. im-bellis, unwarlike (cf. bellum, war).
3. im-pūnis, without punishment (cf. poena, punishment).
4. in-teger, untouched, whole (cf. tangō, to touch, root TAG).
5. in-vītus, unwilling (probably from root seen in vī-s, thou wishest).