4.  Without addition.  Of this formation there are three types:—­

  a) The Verb Stem is reduplicated by prefixing the initial consonant with
  the following vowel or e; as,—­

curro,     Perfect  cu-curri.
posco,        "     po-posci.
pello,        "     pe-puli.

NOTE 1.—­Compounds, with the exception of do, sto, sisto, disco, posco, omit the reduplication.  Thus:  com-puli, but re-poposci.

NOTE 2.—­Verbs beginning with sp or st retain both consonants in the reduplication, but drop s from the stem; as, spondeo, spo-pondi; sto, steti.

  b) The short vowel of the Verb Stem is lengthened; as, lego, legi; ago,
  egi.  Note that a by this process becomes e.

  c) The vowel of the Verb Stem is unchanged; as, verto, verti; minuo,
  minui.

Formation of the Participial Stem.

119.  The Perfect Passive Participle, from which the Participial Stem is derived by dropping -us, is formed:—­

1.  By adding -tus (sometimes to the Present Stem, sometimes to the Verb Stem); as,—­

ama-re, Participle ama-tus. dele-re, " dele-tus, audi-re, " audi-tus, leg-ere, " lec-tus, scrib-ere, " scrip-tus, senti-re, " sen-sus (for sent-tus). caed-ere, " cae-sus (for caed-tus).

  a.  Note that g, before t, becomes c (see Sec. 8, 5); b becomes p; while dt
  or tt becomes ss, which is then often simplified to s (Sec. 8, 2).

2.  After the analogy of Participles like sensus and caesus, where -sus arises by phonetic change, -sus for -tus is added to other Verb Stems; as,—­

lab-i,       Participle  lap-sus.
fig-ere,         "       fi-xus.

  a.  The same consonant changes occur in appending this ending -sus to the
  stem as in the case of the Perfect ending -si (see Sec. 118, 3, a).

3.  A few Verbs form the Participle in -itus; as,—­

doma-re,         dom-itus.
mone-re,         mon-itus.

4.  The Future Active Participle is usually identical in its stem with the Perfect Passive Participle; as, ama-tus, amaturus; moni-tus, moniturus.  But—­

juva-re, Perf.  Partic. jutus, has Fut.  Act.  Partic. juvaturus.[40] lava-re, " " lautus, " " " lavaturus. par-ere, " " partus, " " " pariturus. ru-ere, " " rutus, " " " ruiturus. seca-re, " " sectus, " " " secaturus. fru-i, " " fructus, " " " fruiturus. mor-i, " " mortuus, " " " moriturus. ori-ri, " " ortus, " " " oriturus.

* * * * *

LIST OF THE MOST IMPORTANT VERBS, WITH PRINCIPAL PARTS.

First (A-) Conjugation.