To express the concept if, Klingons attach a type 9 verb suffix on the end of the verb: -chugh.

For example, from bIyIt you walk, you can make bIyItchugh if you walk.

As in English, the if clause can come before or after the result clause:

bIDoy'chugh yIQong! If you are tired, sleep!
yIQong bIDoy'chugh! Sleep, if you are tired!

Because of this, the exercises will often be strict in requiring that you maintain the order of the clauses. When the if clause comes first in the language presented to you, it must also come first in the translation. Similarly, if the result clause comes first in the language presented to you, it must also come first in the translation.

The result clause may start with vaj then, so, thus, in that case, especially when the if clause comes first: e.g. bIDoy'chugh vaj yIQong! If you are tired, then sleep! It is more unusual, but not incorrect to see vaj on the result clause when it comes first: vaj yIQong bIDoy'chugh! Then sleep, if you are tired! It is also common to see the two clauses side by side without using vaj in the result clause.

This unit teaches if sentences with conditions that are considered real or possible. Hypothetical or counterfactual sentences (If you were tired, you would sleep, If I had studied, I would have passed the test, or the like) use a different structure which is not covered in this course.