2172. A very common form of a dependent sentence is that known as the
_Accusative with the Infinitive_.
Thus, of the two coordinate sentences #sciō: iocāris tū nunc#, Pl.
_Most._ 1081, _I know: you are jesting now_, the second may be put in a
dependent form, the two sentences blending into one: #sciō iocārī tē
nunc#, _I know you to be jesting now_.
2173. The subject of an infinitive is put in the accusative.
Thus, in #eum vident#, _they see him_, #eum# is the object of #vident#
(1134). If #sedēre# is added, #eum vident sedēre#, _V._ 5, 107, _they
see him sit_, or _they see that he is sitting_, #eum# is at the same
time the object of #vident# and the subject of #sedēre#. But the
accusative by degrees becoming detached from the main verb, and closely
interlocked with the infinitive, the combination is extended to cases
where the main verb is intransitive or passive.
2174. A predicate noun referring to a subject accusative is itself put
in the accusative: as,
#tē esse arbitror puerum probum#, Pl. _Most._ 949, _I think you are a
good boy_. #nēminem vīvum capī patiuntur#, 8, 35, 5, _they do not allow
anybody to be made prisoner alive_ (2198).