他 動 詞・ 自 動 詞 (transitive/intransitive)
The terms "transitive" and "intransitive" characterize a verb as having a direct object or not. There exist in Japanese several transitive/intransitive verb pairs that use the same verb base and refer to the same action, but differ in that transitive verbs infer that someone is performing the action, while with intransitive verbs no acting agent is implied. Two english equivalents would be the verb pairs raise/rise or lay/lie. All verbs are either transitive or intransitive, though not all verbs have a pair (i.e. 殺す [korosu, to kill]) and some have more than one pair (i.e. 混ぜる [mazeru, to mix]). Many transitive/intransitive verb pairs include one verb with an ending of -as(u) or -ar(u), which are derived from the verbs する (suru, to do - representing transitivity) and ある(aru, to be - representing intransitivity):
In other cases the use of the "e" formative with either a transitive verb or intransitive verb can reverse the transitivity of the verb. Interestingly, when the "e" formative is used in this way it appears to be the potential form of the original verb, however it is not:
Those are the general patterns differentiating transitive and intransitive verb pairs, however there are some irregularities and there is no way to determine by looking at a given verb which of these rules it follows. One must simply learn each verb individually. For a list of some Japanese transitive/intransitive verb pairs click here.
By themselves transitive and intransitive verbs operate much the same as english ones. A transitive verb has a direct object marked by the particle を. An intransitive verb has no direct object. What would be the direct object to the transitive equivalent is instead the subject marked by the particle が:
芋を 燃やしました。 (Someone) burned the potato. [Transitive] 芋が 燃えました。 The potato burned (no agent implied). [Intransitive]
It's important to note that intransitive is not the same as passive form. With passive form an agent may still be implied without being referred to implicitly:
芋が 燃やされました。 The potato was burned (by someone). [Passive Transitive]
In Japanese passive form can be used on both transitive and intransitive verbs, unlike in English where only transitive verbs would be made passive since intransitive verbs are already passive by nature. Consider the following sentence:
芋に 燃えられました。 The potato burned (no agent implied). [Passive Intransitive]
At first it appears to be no different than example 2, however in this case there is an implication that the subject (also implied here, probably the speaker) did not necessarily want the potato burned. This is called the "suffering passive" because the action taking place is being done unto the subject without consent, which usually but not necessarily results in the suffering of the subject to some degree. A looser translation might be something like: The potato burned, much to my dismay," or "The potato went and burned on me," assuming of course that the implied subject is "me."
The suffering passive form also occurs when transitive verbs in passive form act upon a direct object, indicated by the particle を. The agent must be indicated followed by the particle に (unless it has already been established and is known to the listener). Now the action is being done unto the subject without his/her consent:
誰かに 芋を 燃やされました。 The potato was burned by someone (much to my dismay). [Passive Transitive + D.O.]
In the above example the particle に is very important. Simply changing it to が would drastically alter the meaning of the sentence. 誰か would become the subject, replacing the actual implied subject, and the passive form would be misconstrued as honorific. So it would read something like: "Someone (probably very important) did the honor of burning the potato."