Transitivity of suru-verbs and the causative form to turn intransitive suru verbs into transitive ones


Recently came upon sentences where the causative form is used to make a suru-
verb a transitive one.

eg. この城を完成させるのに、...

Are all suru verbs, intransitive by default? If so, does this use of the
causative form apply to all suru-verbs?




**Update to previous comment**

Transitivity/intransitivity is a function of whether the verb takes a direct
object or not. So as long as the する verb can take a direct object, it can be
said to be transitive.

However, having done a little bit of research on this now, it seems there are
many する words that are called "ergative verbs", or 能{のう}格{かく}動{どう}詞{し}. Such
verbs can be both transitive and intransitive, as T.Allred already mentioned.
完成する would fall into this category. Others would include the following, as per
Japanese Wikipedia:

「閉鎖する」（「工場を閉鎖する」「工場が閉鎖する」）、「生成する」、「連続する」、「停止する」など

Unfortunately, it seems that the typically straightforward rules of
conjugation in Japanese fall apart when it comes to transitive/intransitive する
verbs. Based on everything I've been able to find on the subject, it seems
that the best way to determine the status of a する verb is to A) find as many
sample sentences as you can (via jisho.org, etc) to determine the most common
usage, or B) rely on an actual comprehensive physical Japanese dictionary, as
they apparently make notations regarding the status of each verb.




**Update to previous comment**

Transitivity/intransitivity is a function of whether the verb takes a direct
object or not. So as long as the する verb can take a direct object, it can be
said to be transitive.

However, having done a little bit of research on this now, it seems there are
many する words that are called "ergative verbs", or 能{のう}格{かく}動{どう}詞{し}. Such
verbs can be both transitive and intransitive, as T.Allred already mentioned.
完成する would fall into this category. Others would include the following, as per
Japanese Wikipedia:

「閉鎖する」（「工場を閉鎖する」「工場が閉鎖する」）、「生成する」、「連続する」、「停止する」など

Unfortunately, it seems that the typically straightforward rules of
conjugation in Japanese fall apart when it comes to transitive/intransitive する
verbs. Based on everything I've been able to find on the subject, it seems
that the best way to determine the status of a する verb is to A) find as many
sample sentences as you can (via jisho.org, etc) to determine the most common
usage, or B) rely on an actual comprehensive physical Japanese dictionary, as
they apparently make notations regarding the status of each verb.

