ubi\ is called a _relative conjunction_ because it is equivalent to a relative pronoun. _When_ in the first sentence is equivalent to _at the time at which\;_ and in the second, where is equivalent to the place /in which\.

208. The following list shows the principal parts of all the verbs you have had excepting those used in the paradigms.  The parts you have had before are given for review, and the perfect participle is the only new form for you to learn.  Sometimes one or more of the principal parts are lacking, which means that the verb has no forms based on that stem.  A few verbs lack the perfect passive participle but have the future active participle in -u:rus, which appears in the principal parts instead.

  IRREGULAR VERBS

sum     esse     fui:     futu:rus    be
absum   abesse   a:fui:    a:futu:rus   be away
do:[1]   dare     dedi:    datus      give

    [Footnote 1:  do:\ is best classed with the irregular verbs because
    of the short a\ in the present and participial stems.]

  CONJUGATION I

  porto:  porta:re porta:vi:  porta:tus carry

  So for all verbs of this conjugation thus far used.

  CONJUGATION II

contineo:  contine:re continui:  contentus hold in, keep de:leo:  de:le:re de:le:vi:  de:le:tus destroy doceo:  doce:re docui:  doctus teach egeo:  ege:re egui:  ——­ lack faveo:  fave:re fa:vi:  fautu:rus favor iubeo:  iube:re iussi:  iussus order moveo:  move:re mo:vi:  mo:tus move noceo:  noce:re nocui:  nocitu:rus injure pa:reo:  pa:re:re pa:rui:  ——­ obey persua:deo:  persua:de:re persua:si:  persua:sus persuade (from) prohibeo:  prohibe:re prohibui:  prohibitus restrain, keep respondeo:  responde:re respondi:  respo:nsus reply sedeo:  sede:re se:di:  -sessus sit studeo:  stude:re studui:  ——­ be eager video:  vide:re vi:di:  vi:sus see

  CONJUGATION III

ago:  agere e:gi:  a:ctus drive cre:do:  cre:dere cre:didi:  cre:ditus believe di:co:  di:cere di:xi:  dictus say disce:do:  disce:dere discessi:  discessus depart du:co:  du:cere du:xi:  ductus lead facio:[2] facere fe:ci:  factus make fugio:  fugere fu:gi:  fugitu:rus flee iacio:  iacere ie:ci:  iactus hurl interficio:  interficere interfe:ci:  interfectus kill mitto:  mittere mi:si:  missus send rapio:  rapere rapui:  raptus seize resisto:  resistere restiti:  ——­ resist

  CONJUGATION IV