The basic meaning of wakeda is to express the speaker's attitude of recognizing that there is a logical relationship between two events. Since hazuda and kotoninaru also have such a meaning, it is difficult for Japanese learners to use them properly. In order to explain the difference between the usage of wakeda and that of hazuda and kotoninaru, sentences belonging to the five categories of wakeda are analyzed from the viewpoint of whether wakeda can be replaced by hazuda or kotoninaru.
Basically, there are the following differences among the three expressions. Wakeda expresses subjective conclusion out of logical thinking, hazuda expresses inference out of logical thinking, and kotoninaru expresses objective conclusion out of logical thinking.
Hazuda or kotoninaru can replace wakeda of the first category, in which the speaker expresses an attitude of recognizing the result of an event. Neither Hazuda nor kotoninaru can replace wakeda of the second category, in which the speaker expresses an attitude of recognizing the cause of an event. Wakeda of the third category, in which the speaker expresses an attitude of understanding of the relationship between a cause and a result, can be replaced by only hazuda. Wakeda of the fourth category, in which the speaker presents another interpretation of an event, can be replaced by only kotoninaru. Neither Hazuda nor kotoninaru can replace wakeda of the fifth category, which is used in casual conversation in order to give an emphasis to a fact when the speaker thinks the hearer does not know it.