Pseudo Cleft Sentences are similar in function to cleft sentences, but they are formed with the pronoun “what.” They also have a clause that substitutes a noun phrase and acts as the subject of the whole sentence. What I like about them is how they emphasize selected parts.
What John took Mary to was a concert.
She said that what was great about visiting Doug O’Brien’s blog was how much you learn.
What is important is integrity.