将来时                          过去时                         现在时

          第一人称                ero                               eram                             sum

单数   第二人称                eris                              eras                               es

         第三人称                 erit                                erat                               est

          第一人称                erimus                          eramus                          sumus

复数   第二人称                eritis                             eratis                             estis

         第三人称                erunt                             erant                              sunt

                                       将来时                          过去时                             现在时

          第一人称                 potero                         poteram                          possum

单数   第二人称                poteris                        poteras                          potes

         第三人称                 poterit                         poterat                            potest

          第一人称                poterimus                    poteramus                       possumus

复数   第二人称                poteritis                        poteratis                          potestis

         第三人称                poterunt                         poterant                          possunt

补足不定式

用于情态动词后

Our friends were able to overcome many dangers.

Amici nostri poterant superare multa pericula.

My friend is not able to remain.

Amicus meus non potest remanere.

You ought to save your money.

Debes conservare pecuniam tuam.

补足不定式没有自己的独立主语；他的主语与他所依靠的动词主语相同。