A transitive verb (他動詞, たどうし, tadoushi) has an active agent, while an intransitive verb (自動詞, じどうし, jidoushi) doesn't, and the action "happens by itself". For example:
Transitive pattern -> 冷蔵庫にバターを入れた (れいぞうこにバターをいれた, reizouko ni bata- wo ireta) - I put the butter in the refrigerator;
Intransitive pattern -> 家に入った (いえにはいった, ie ni haitta) - I entered the house.
As you can see, it has a thing in common: the kanji. Therefore, the meaning as well, which is "to put something inside another thing". In the first case, the butter goes inside the refrigerator, and in the second case, the subject goes inside the house.
These two patterns have different dictionary forms, which are 入れる (いれる, ireru) (T) and 入る (はいる, hairu) (I). There is not a direct way to get both patterns, it's a matter of memorizing. Sometimes they resemble each other though.
So I leave here a short list of some verbs in both patterns:
|入れる (いれる, ireru)||to put in, to insert||入る (はいる, hairu)||to get in, to enter|
|出す (だす, dasu)||to put out, to deliver||出る (でる, deru)||to get out, to exit|
|落とす (おとす, otosu)||to drop||落ちる (おちる, ochiru)||to fall|
|壊す (こわす, kowasu)||to break (something)||壊れる (こわれる, kowareru)||to break|
|開ける (あける, akeru)||to open (something)||開く (あく, aku)||to open|
|閉める (しめる, shimeru)||to close (something)||閉まる (しまる, shimaru)||to close|
We are almost entering the intermediate level! Prepare yourself! :D