406. A clause of purpose or of result may be either an adverbial clause (as in [§ 403]) or a substantive clause.

407. A substantive clause of purpose is often used as the object of a verb of commanding, desiring, or the like.

408. For subordinate clauses with shall or should, implying purpose or expectation, see [§ 304].

409. Purpose may be expressed by the infinitive with to or in order to, and result by the infinitive with to or as to.

Negative result is often expressed by the adverb too and the infinitive.

Iron is too heavy to float. [Compare: Iron is so heavy that it does not float.]

410. Purpose may be expressed by an infinitive clause ([§ 325]).