You might have learned the difference between transitive verb and intransitive verb, and probably it was not so difficult to understand the differences. However, you might have had difficulty remembering them.
There are some rules to form transitive verb and intransitive verb. The following rules might help you to remember them:
1) All verbs that end with -aru are Intransitive verb , and you can form transitive verb by changing -aru with -eru.
In the list below, on the left is intransitive verb and on the right is transitive verb
Examples 1-1) - aru : -eru 閉まる 閉める 終わる 終える
変わる 変える 始まる 始める 上がる 上げる 下がる 下げる 集まる 集める
2) All verbs that end with -reru are intransitive verb
2-1) -reru : - su 倒れる 倒す 汚れる 汚す 壊れる 壊す 隠れる 隠す
2-2) -reru : -ru 割れる 割る 破れる 破る 売れる 売る 切れる 切る
3) All verbs that end with -su are transitive verb