Causative form and willingness of the cast


According to "A dictionary of basic Japanese grammar" pg. 389 (on the choice
between に and を particles with causative form)

> When _ni_ is used, the causee has taken an action _intentionally_.

I have trouble understanding that, as they give an example of

> 父は私 **を** (not に) むりやりパーティーへ行かせた。

Supposedly に is ungrammatical in this situation as the subject did not intend
to go to the party. But aren't the vast majority of cases where you want to
make someone do sth. involuntary? At the same time, in the Genki II textbook
(second ed. pg. 234-236) there are examples of sentences using "に" where it is
implied that a person made someone do sth. against their intention, like

> お母さんは子供に本を読ませました

So my question is what are the actual rules of using に with causative verbs.




Your book quote is specifically for intransitve verbs. Page 390 of the same
book says:

> If the main verb is transitive, the causee can only be marked by ni.

In your example お母さんは子供に本を読ませました the verb 読む is transitive.




Your book quote is specifically for intransitve verbs. Page 390 of the same
book says:

> If the main verb is transitive, the causee can only be marked by ni.

In your example お母さんは子供に本を読ませました the verb 読む is transitive.

