In this study I shall deal with topicalized and cleft constructions. Topicalized and cleft sentences are very similar in form and serve a similar function--to focus attention on some item. The main purpose in analysing these constructions is to account for the fact that structures exhibiting the same apparent form do not necessarily behave in the same way with regard to topicalization and clefting.
Moir, M. (1982). A predicational approach to topicalization and clefting. Calgary Working Papers in Linguistics, 8(Fall), 51-106.