For the most part, these are straightforward and uncomplicated: a sumti that is part of a relative clause bridi may itself be modified by a relative clause:
10.1) le prenu poi zvati le kumfa poi blanu cu masno
The person who is-in the room which is-blue is-slow.
However, an ambiguity can exist if “ke'a” is used in a relative clause within a relative clause: does it refer to the outermost sumti, or to the sumti within the outer relative clause to which the inner relative clause is attached? The latter. To refer to the former, use a subscript on “ke'a”:
10.2) le prenu poi zvati le kumfa poi ke'axire zbasu ke'a cu masno
The person who is-in the room which IT-sub-2 built IT is-slow.
The person who is in the room which he built is slow.
Here, the meaning of “IT-sub-2” is that sumti attached to the second relative clause, counting from the innermost, is used. Therefore, “ke'axipa” (IT-sub-1) means the same as plain “ke'a”.
Alternatively, you can use a prenex (explained in full in Chapter 16), which is syntactically a series of sumti followed by the special cmavo “zo'u”, prefixed to the relative clause bridi:
10.3) le prenu poi ke'a goi ko'a zo'u ko'a zvati le kumfa
poi ke'a goi ko'e zo'u ko'a zbasu ke'a cu masno
The man who (IT = it1 : it1 is-in the room
which (IT = it2 : it1 built it2) is-slow.
Example 10.3 is more verbose than Example 10.2, but may be clearer, since it explicitly spells out the two “ke'a” cmavo, each on its own level, and assigns them to the assignable cmavo “ko'a” and “ko'e” (explained in Chapter Chapter 6).