The following cmavo are discussed in this section:

There are types of relative clauses (those which have a certain selbri) which are frequently wanted in Lojban, and can be expressed using a shortcut called a relative phrase. Relative phrases are introduced by cmavo of selma'o GOI, and consist of a GOI cmavo followed by a single sumti.

Here is an example of pe, plus an equivalent sentence using a relative clause:

In Example 8.18 and Example 8.19, the link between the chair and the speaker is of the loosest kind.

Here is an example of po:

Example 8.20 and Example 8.21 contrast with Example 8.18 and Example 8.19: the chair is more permanently connected with the speaker. A plausible (though not the only possible) contrast between Example 8.18 and Example 8.20 is that pe mi would be appropriate for a chair the speaker is currently sitting on (whether or not the speaker owned that chair), and po mi for a chair owned by the speaker (whether or not he or she was currently occupying it).

As a result, the relationship expressed between two sumti by po is usually called “possession”, although it does not necessarily imply ownership, legal or otherwise. The central concept is that of specificity (steci in Lojban).

Here is an example of po'e, as well as another example of po:

Example 8.22 and Example 8.23 on the one hand, and Example 8.24 on the other, illustrate the contrast between two types of possession called “intrinsic” and “extrinsic”, or sometimes “inalienable” and “alienable”, respectively. Something is intrinsically (or inalienably) possessed by someone if the possession is part of the possessor, and cannot be changed without changing the possessor. In the case of Example 8.22, people are usually taken to intrinsically possess their arms: even if an arm is cut off, it remains the arm of that person. (If the arm is transplanted to another person, however, it becomes intrinsically possessed by the new user, though, so intrinsic possession is a matter of degree.)

By contrast, the bottle of Example 8.24 can be given away, or thrown away, or lost, or stolen, so it is possessed extrinsically (alienably). The exact line between intrinsic and extrinsic possession is culturally dependent. The U.S. Declaration of Independence speaks of the “inalienable rights” of men, but just what those rights are, and even whether the concept makes sense at all, varies from culture to culture.

Note that Example 8.22 can also be expressed without a relative clause:

reflecting the fact that the gismu birka has an x2 place representing the body to which the arm belongs. Many, but not all, cases of intrinsic possession can be thus covered without using po'e by placing the possessor into the appropriate place of the description selbri.

Here is an example of po'u:

The cmavo po'u does not represent possession at all, but rather identity. (Note that it means poi du and its form was chosen to suggest the relationship.)

In Example 8.26, the use of po'u tells us that le gerku and le mi pendo represent the same thing. Consider the contrast between Example 8.26 and:

The facts of the case are the same, but the listener's knowledge about the situation may not be. In Example 8.26, the listener is presumed not to understand which dog is meant by le gerku, so the speaker adds a relative phrase clarifying that it is the particular dog which is the speaker's friend.

Example 8.28, however, assumes that the listener does not know which of the speaker's friends is referred to, and specifies that it is the friend that is the dog (which dog is taken to be obvious). Here is another example of the same contrast:

The principle that the possessor and the possessed may change places applies to all the GOI cmavo, and allows for the possibility of odd effects:

Example 8.31 is useful in a context which is about my friend, and states that his or her cup is small, whereas Example 8.32 is useful in a context that is primarily about a certain cup, and makes a claim about “my friend of the cup”, as opposed to some other friend of mine. Here the cup appears to “possess” the person! English can't even express this relationship with a possessive – “the cup's friend of mine” looks like nonsense – but Lojban has no trouble doing so.

Finally, the cmavo ne and no'u stand to pe and po'u, respectively, as noi does to poi- they provide incidental information:

In Example 8.33, the white dog is already fully identified (after all, presumably the listener knows which dog bit him or her!). The fact that it is yours is merely incidental to the main bridi claim.

Distinguishing between po'u and no'u can be a little tricky. Consider a room with several men in it, one of whom is named Jim. If you don't know their names, I might say:

Here I am saying that one of the men is a poet, and incidentally telling you that he is Jim. But if you do know the names, then

is appropriate. Now I am using the fact that the man I am speaking of is Jim in order to pick out which man I mean.

It is worth mentioning that English sometimes over-specifies possession from the Lojban point of view (and the point of view of many other languages, including ones closely related to English). The idiomatic English sentence

seems strange to a French- or German-speaking person: whose pockets would he put his hands into? and even odder, whose hands would he put into his pockets? In Lojban, the sentence

is very natural. Of course, if the man is in fact putting his hands into another's pockets, or another's hands into his pockets, the fact can be specified.

Finally, the elidable terminator for GOI cmavo is ge'u of selma'o GEhU; it is almost never required. However, if a logical connective immediately follows a sumti modified by a relative phrase, then an explicit ge'u is needed to allow the connective to affect the relativized sumti rather than the sumti of the relative phrase. (What about the cmavo after which selma'o GOI is named? It is discussed in Section 7.5, as it is not semantically akin to the other kinds of relative phrases, although the syntax is the same.)