さてWell, Well then

Both mark transitions, but with slightly different nuance. さて is used to shift to a new topic or proceed to the next step, e.g. さて、次の話題に入りましょう ('Now then, let's move on to the next topic.') では・それでは・じゃあ reference the previous context and often lead into a decision or conclusion, similar to 'well then' or 'in that case', e.g. それでは、始めましょう ('Well then, let's begin.')

These are two similar-looking interjections with different uses. さて is a transitional phrase often used at the beginning of sentences to change the topic or move the conversation into a new phase, like 'well then' or 'now then'. In contrast, さ is a casual interjection that serves multiple functions, such as encouragement (e.g. 'all right!', 'come on!') or hesitation ('well, you see...').