Please discuss what the predicative dative is and when is it used?
Commonly, the verb "to be" (sum, esse, fui) is followed by a complement. This complement is a word which has the same number, gender and case (nominative) as the subject of the verb. It is not a direct object of the verb and so is not in the accusative case.
Illi pueri sunt ingentes.
Illi pueri puellam amant.
In the first sentence, "pueri" and "ingentes" are nominative, plural and masculine. "ingentes" is a complement. In the second sentence, "pueri" is nominative, plural and masculine; "puellam" is accusative, singular and feminine. "puellam" is the direct object of the verb.
Sometimes, the verb "to be" is followed by a ...
The solution discusses predicative dative and when it is used.