On grammatical class:

ba
time tense relation/direction: will [selbri]; after [sumti]; default future tense.
ca
time tense relation/direction: is [selbri]; during/simultaneous with [sumti]; present tense.
pu
time tense relation/direction: did [selbri]; before/prior to [sumti]; default past tense.
baba
time tense: will be going to; (tense/modal).
baca'a
time tense: future actuality; modal aspect.
bapu
time tense: will have been; (tense/modal).
ca ma
sumti question asking for a time/date/event; simultaneous with what?.
caca'a
time tense: present actuality; modal aspect.
cajeba
time tense: during and after; (tense/modal).
caku
Now. At the present time.
puba
time tense: was going to; (tense/modal).
puca'a
time tense: past actuality; modal aspect.
pujeba
time tense: before and after; (tense/modal).
pujeca
time tense: before and during; (tense/modal).
pupu
time tense: had earlier been; (tense/modal).
puza
time tense: a medium time before; (tense/modal).
puze'a
time tense: for a medium length interval some time in the past; (tense/modal).
puze'i
time tense: for a short interval some time in the past; (tense/modal).
puze'u
time tense: for a long interval some time in the past; (tense/modal).
puzi
time tense: a short time before; (tense/modal).
puzu
time tense: a long time before; (tense/modal).