In the first sentence, the cognate object (daggers) modifies the predicate verb (looked) as the adverb angrily would do. It is therefore an adverbial modifier. In the second and third sentences the modifier of the predicate verb (sang, laughed) is an adverbial phrase consisting of a cognate object (song, laugh) with its adjective modifiers (a merry, a scornful).

CHAPTER IV
COMPLEMENTS

482. 1. Some verbs have a meaning that is complete in itself. Such a verb needs only a subject. When this has been supplied, we have a sentence, for the mere verb, without any additional word or words, is capable of being a predicate.

Verbs of this kind are sometimes called complete verbs, or verbs of complete predication.

2. Other verbs are not, by themselves, capable of serving as predicates. Thus,—

These are not sentences, for the predicate of each is unfinished. The verb requires the addition of a substantive or an adjective to complete its sense.