A natural language generally has a variety of kinds of clauses that can be embedded in sentences. "Going out to lunch" in "Going out to lunch would be a good idea" is a nominal clause, because it acts as a noun in the sentence. (To check, substitute a noun: "A wall here would be a good idea.") "That you know" in "I know that you know" is another kind of clause. "Which was too far away" in "We rejected Luigi's, which was too far away" is a relative clause, modifying "Luigi's".

Ouxu has only one kind of clause, but it can serve all the purposes of natural language clauses because it is inflected as if it were a single word.

noun noun ... clause+inflection

Grammatically, a clause is a sentence minus the divider. The sentence is followed by the special root he-, which marks the end of the clause. He- is inflected like any other element of the larger sentence, and the clause as a whole plays the role in the larger sentence which the inflection declares.

uescoenae hotopoha heua
home+city+experiencer build+opposite+action clause+goal
to want to destroy my town

Pa uescoenae hotopoha heua ipatehso ogpafuaata.
Belief home+city+experiencer build+opposite+action clause+goal large+very+attribute device+person+agent.
Giant robots want to destroy my town.

Pa uescoenae hotopoha heua ipatehso ogpafuaata hepe ofae hogeun.
Belief home+city+experiencer build+opposite+action clause+goal large+very+attribute device+person+agent clause+exist I+experiencer familiar-with+change-to.
I found out that giant robots want to destroy my town.

As shown above, clauses can be nested. A clause can be used anywhere and inflected in any way, as appropriate to the meaning. If a clause uses a subordinating inflection, of course it must appear immediately before whatever it is modifying.

ipatpoko xatpe heso
large+opposite+and green+exist clause+attribute
which were small and green

Uescoenae hotopoha heua pa ipatpoko xatpe heso elelafuaahuata.
Home+city+experiencer build+opposite+action clause+goal belief
large+opposite+and green+exist clause+attribute outer-space+person+also+agent.
The space aliens, who were small and green, also wanted to destroy my town.

In the above example, you might more simply say xatelelafuaaunta (small green space aliens). Breaking out "small and green" into a clause is a stylistic choice. By using a less tightly-bound grammatical form, it suggests that the information is less central.

A clause cannot be split across the divider. A clause is a single sentence element and acts as if it were a single word; though some parts of it may be known to the listener, it is the clause as a whole that must be placed before or after the divider, depending on its status.

If you add a derivational suffix to the clause ender, it applies to the whole clause. The same goes for compounding another root with the clause ender.

Soxe pa sapafae kieaae puotfa heuohuxu.
Romantic-love+whole belief the-moon+experiencer earth+experiencer collision+event clause+repeating+part.
It's a the-moon-keeps-crashing-into-the-earth kind of love.

There is no marker to let you know when a clause begins. Because of that, a sentence with a clause is in general grammatically ambiguous: You can't tell for sure which words belong to the clause and which belong directly to the larger sentence. This is true of natural languages too, but we rarely notice because the meaning and context of the sentence snatch out the correct interpretation and force it on us without our awareness.

Where there is risk of ambiguity, it is good style to put a clause first in the sentence, or to start it immediately after the divider. The natural barrier will serve to mark the start of the clause.