Klingon verbs ending in Type 9 suffixes (other than -'a' interrogative and -wI' one who does, one which does) always occur in sentences with another verb. Hence, they are verbs in subordinate clauses.

cha yIbaH qara'DI' or qara'DI' cha yIbaH
Fire the torpedoes at my command!

The two parts of this sentence are cha yIbaH fire the torpedoes! and qara'DI' when I command you or as soon as I command you. -DI' is a Type 9 suffix meaning as soon as, when, so qara'DI' must occur as part of a larger sentence. Note that the order of the two parts of the sentence is variable.

A few further examples should make the use of subordinate clauses clear.

bIjatlhHa'chugh qaHoH or qaHoH bIjatlhHa'chugh 
If you say the wrong thing, I will kill you.
(bIjatlhHa'chugh if you misspeak, qaHoH I kill you)

Note that although the English translation uses the word will, there is no marker for future in Klingon. The unsuffixed verb HoH kill is neutral as to time: since the person being addressed is being given a chance to speak, that person must still be alive. Thus, the killing must take place in the future.

SutlhtaHvIS chaH DIHIvpu' or DIHIvpu' SutlhtaHvIS chaH
While they were negotiating we attacked them.
(SutlhtaHvIS while they are negotiating, chaH they, DIHIvpu' we attacked them)

The notion of were negotiating, rather than are negotiating, comes from the suffix -pu' perfective attached to the verb HIv attack. A translation such as While they are negotiating we attacked them makes little sense in English and misrepresents the meaning of the Klingon sentence.