*** Guide-to-Links ***
QI connects certain verbs and adjectives to question-words, forming
indirect questions:
	       |      |
	1. I wonder what book he will read    	
	2. I wonder what will happen
	3. I wonder what he will do
	4. I wonder when he will come
	5. I wonder how big it is

                       |      |
	6. I am not certain where he is

Question-words thus have "(QI- or W-)". (The W- is used in
direct questions, to attach to the wall.) This is conjoined
with various connectors.  Determiner question-words, like
ex. 1 above, use D**w+; subject-type questions (ex.2) use
Ss*w+; object-type questions (ex.3) use B*w+; where/when/how
questions (ex.4) use Cs+, PF+ or TOn+; adjective questions
(ex.5) use EAh+. See entries for these individual link-types.

Verbs ("wonder", "know", "ask") and adjectives ("certain",
"clear") that take indirect questions have QI+, disjoined with
other complement connectors.

QIi is used by post-processing to enforce the correct use of
"filler-it".  Certain phrases can only be used with "it" as
the subject ("It is not clear what will happen"; *"I am not
clear what will happen"); this is enforced in
post-processing. "QIi" is therefore directly analagous to
"THi" (see "SF: filler-it").

QI#d is, similarly, used by post-processing. The issue here is
whether or not the QI link should begin a domain. In all
indirect questions, it is clear that the indirect question
should be in a different group from what precedes.  With
"where/when/how" constructions ("I wonder when he will come");
the question-word makes a Cs connection to the new subject,
beginning an 's' domain; thus the QI link need not start a
domain itself. In all other cases, however, the links
extending to the right of the question-word (B, S, D, etc.)
are not normally domain-starting. In these cases, then, the QI
link has to start the domain. Thus we make "QI#d+" a
domain-starting link, and assign it to question-words like
"what" and "who"; "where", "when" and "how" have the
non-domain-starting "QI+".

Grammar Documentation Page.