I like to think of Klingon verbs as ALWAYS having a prefix. Sure the prefix may be the null prefix (in other words you can't see it and can't hear it), but some information on who is the subject and who is the object is always there, even when it appears there is nothing there. val is presented as a sentence (notice the period), thus someone must be doing the action. This invisible and silent prefix we call the null prefix (or the absence of a prefix if you prefer) indicates that the subject is third person (it can be singular or plural - he/she/it/they) and that the object is either absent or also third person (him/her/it/them). In Klingon, it is OK to leave that subject unstated and unspecified, but in English, "Smart," is not a sentence and the subject must be stated. So pick one of the options (he/she/it/they) and say it. In this case, the most likely subject is still Torg, so we use "he is".