Exclamative Clauses

Halliday & Matthiessen (2014: 164):

These clauses have the WH- element what or how, in nominal or adverbial group. … what conflates with a Complement, as in what tremendously easy riddles you ask; this is often an attributive Complement, as in what a fool he is. how conflates with an Adjunct, as in how beautifully you make love. In earlier English the Finite in these clauses preceded the Subject, as in how are the mighty fallen; but since the Finite ^ Subject sequence became specifically associated with the interrogative mood, the normal order in exclamatives has become Subject ^ Finite.