出(だ)すTo suddenly begin, To start doing

おわる and だす both attach to verb stems but express opposite ideas, like finishing vs. starting an action. おわる is used for completing almost any action, e.g. 本を読み終わった ('I finished reading the book.'). だす often describes actions that begin suddenly or unexpectedly, e.g. 雨が降り出した ('It started to rain.').

Both だす and いきなり express sudden action, but they differ in usage. だす attaches to verb stems to mean 'to suddenly start doing something.' For example, 動き出す 'begin to move'. In contrast, いきなり appears before verbs or phrases, like 'suddenly' in English. They can also be used together, as in いきなり動き出した ('It suddenly started moving.').

かけ and だす both attach to verb stems and can express the start of an action, but their nuance differs. かけ emphasizes that the action has begun but remains incomplete. For example, 書きかけの小説 'a partially written/incomplete novel.' In contrast, だす highlights the beginning of the action, often with a sense of suddenness. For example, 書き出した ('He suddenly started writing.').

Both はじめる and だす attach to verb stems to mean 'to start doing (A)', but with different nuances. はじめる implies a deliberate or planned action, e.g. 学びはじめた ('I began to learn.'). In contrast, だす conveys a more spontaneous or unexpected beginning, e.g. 雨が降りだした ('It suddenly began to rain.').