Translation guide
The primary reason or source of something. In Japanese, this is commonly expressed with 主な原因 (omo na gen'in) or 主因 (shuin).
Expressing the most important factor that leads to a result.
The most common and neutral way to say 'main cause'. Suitable for both spoken and written contexts.
事故の主な原因はスピードの出し過ぎだった。
The main cause of the accident was excessive speed.
A more formal or technical term for 'main cause', often used in written reports or academic contexts.
Literally 'the number one cause'. More conversational and emphatic than 主な原因.
遅刻の一番の原因は寝坊です。
The main cause of being late is oversleeping.
Means 'the biggest factor'. Used when emphasizing the scale or impact of a cause, often in analytical contexts.
景気後退の最大の要因は消費の落ち込みだ。
The main cause of the recession is the drop in consumption.
The main cause of this disease has not yet been identified.