た途端(とたん)にBegitu..., Segera setelah, Tepat ketika

Both express actions occurring in close sequence, but differ in focus. たとたんに emphasizes the precise moment with suddenness, e.g. 'ドアを開けたとたんに猫が飛び出した' ('The moment I opened the door, the cat jumped out'). かと思ったら・かと思うと marks a quick change with surprise, e.g. '晴れたかと思ったら、すぐに雨が降り出した' ('Just when I thought it cleared up, it started raining again').

たところだ dan たとたんに sama-sama merujuk pada sesuatu yang baru saja terjadi, tetapi nuansanya berbeda. たところだ hanya menjelaskan waktu kejadian, misalnya 家に帰ってきたところだ ("Aku baru saja sampai di rumah"). Sebaliknya, とたんに menyatakan bahwa sesuatu terjadi tepat pada saat itu juga, misalnya 家に帰ってきたとたんに雨が降ってきた ("Begitu aku sampai di rumah, hujan langsung turun").

直ちに and たとたんに both indicate swift timing, but differ in tone and structure. 直ちに is formal and emphasizes urgency, e.g. '直ちに避難してください' ('Please evacuate immediately'). たとたんに conveys something happening instantly after another event, often with surprise, e.g. '顔を見たとたんに泣き出した' ('She started crying the moment she saw his face').

Keduanya merujuk pada sesuatu yang baru saja terjadi, tetapi berbeda dalam nuansa. たばかり menggambarkan keadaan setelah suatu tindakan selesai, misalnya 帰ってきたばかり ('baru saja pulang'). Sementara itu, とたんに menunjukkan sesuatu terjadi tepat pada saat hal lain terjadi, misalnya 帰ってきたとたんに雨が降った ("Begitu aku sampai di rumah, hujan mulai turun").

Both と同時に and たとたんに describe closely linked events, but they differ in focus. と同時に emphasizes simultaneity or coordination, while たとたんに conveys a sudden, often unexpected result following a completed action. Their grammar structure also differs: と同時に follows the non-past form, while たとたんに follows the past tense.

Both describe sequences where one action quickly follows another, but differ in tone and formality. 次第 is formal and indicates that an action will follow as soon as another is completed, e.g. '会議が終わり次第、報告します' ('I'll report as soon as the meeting ends'). たとたんに emphasizes sudden or unexpected results, often in conversation, e.g. 'ドアを開けたとたんに猫が飛び出した' ('The moment I opened the door, the cat jumped out').

Both express immediacy following another action, but differ in nuance and tone. たとたんに stresses suddenness or unexpectedness, sometimes with emotion, e.g. '立ち上がったとたんに倒れた' ('He collapsed the moment he stood up'). なり also marks instantaneousness, but feels more formal or literary, and implies a natural cause-effect link, e.g. '席に着くなり、食べ始めた' ('As soon as he sat down, he started eating').