Click on SLIDESHARE or on CLEFT to view a general explanation.
Remember the 2 most common types are WHAT and IT clauses.
The structures depend on where we wish to put the emphasis:
- focus on an action: WHAT+ S+ do+be+ (S)+ infinitive (plain, without to)
- emphasis on a whole sentence: WHAT+ happen+ be+ SVO
+++ the person (who).../ the reason (why).../ the place (where).../ the time (when)...
+infml+ the thing/ all/ something... + relative + be
- specific information : IT+ be (singular) + info+ relative clause (that/who)