"The clever warrior sleeps."
Translation:Qong SuvwI' val.
This is the first time I see an adjective describing a noun. If you put it after the noun does it lose the verb and stop meaning "to be clever"?
No. But I'm a little confused by your question. Let's start by making sure we are using the correct terminology. The subject is the one doing the action. The object is the one that the action is done to. They are both nouns (or noun phrases). A verb is the action (though in Klingon sometimes it's more a state or a quality). An adjective is a word that describes a noun.
In English the basic sentence structure is Subject-Verb-(Object). Sometimes there is no object as in, "The warrior sleeps." In this case, "the warrior" is the subject and "sleeps" is the verb and the verb is the last word. Sometimes there is an object as in, "The warrior fights an enemy." In this case, "the warrior" is the subject, "fights" is the verb, and "an enemy" is the object and the object is, indeed, the last word. Even if we add in an adjective, it usually appears before the noun as in, "The smart warrior fight a strong enemy," so the object would still be the last word. However, in English, there can sometimes be additional information after the object as in, "The warrior fights an enemy in the holodeck." In English the object is often the last word, but definitely not always.
In Klingon the basic sentence structure is (Object)-Verb-Subject. Sometimes there is no object as in, Qong SuvwI'. In this case, SuvwI' is the subject and Qong is the verb and the subject is the last word. Sometimes there is an object as in, jagh Suv SuvwI'. In this case, SuvwI' is the subject, Suv is the verb, and jagh is the object and the subject is, again, the last word. In Klingon the subject is very often the last word in the sentence and I wonder if you meant to ask if the subject of a Klingon sentence is always the last word. However, if we add a stative/qualitative verb onto the subject acting as an adjective, it goes after the noun as in, jagh HoS Suv SuvwI' val ("The smart warrior fights a strong enemy."), but when we do that the adjectival verb val is now considered part of the subject noun phrase, so we still say that the subject is last, but the actual last word is a verb acting like an adjective within the subject. It is almost always true that the subject is the last thing in the sentence (though the last word may not actually be a noun), however, there are some exceptions. For instance, there is a word jay' which is often translated as if it were a swear word (the best description I've heard is that it makes a regular sentence sound like a sentence said by Samuel L. Jackson) and that word always comes at the end of the sentence, after the subject.
Does this help you, or have I still not understood or answered your question fully?
I regret to see you have no reply to such a well-written and fully-fledged explanation. I do not know about the sethron23, but it helped me. Keep up the good work!