The words "because," "since," "for," and "as" can all express causation, but their usage depends on context, tone, and formality. Here's when they can be interchangeable and when they differ: 1. "Because" Meaning: Directly explains the reason for something. Usage: Most commonly used in both spoken and written English for clear, straightforward explanations. Example: "I stayed home because it was raining." 2. "Since" Meaning: Indicates causation (like "because") or time (as in "from a certain time"). Usage: More formal and less direct than "because" for reasons. Often used in writing. Example (causation): "I stayed home since it was raining." Interchangeable? Yes, but "since" can sound softer or imply that the reason is already known. 3. "For" Meaning: Formal, literary way of introducing a reason or justification. Usage: Rare in modern conversation but common in literary or formal writing. Often connects two clauses. Example: "I stayed home, for it was raining." Interchangeable? Sometimes with "because," but "for" typically sounds old-fashioned or poetic. 4. "As" Meaning: Indicates a cause or reason; also used for comparisons and time relationships. Usage: Formal, often when the reason is less emphasized. Example: "I stayed home as it was raining." Interchangeable? Yes, with "because" and "since," but "as" is often used when the reason is secondary to the main idea. Key Interchangeable Cases "Because," "since," and "as" are often interchangeable when explaining reasons: "He was late because/since/as he missed the bus." "For" is interchangeable with "because" only in formal or literary contexts: "I left early, for I was feeling unwell." Non-Interchangeable Cases "Since" with Time: "Since last year, I've been working here." Cannot replace with "because," "for," or "as." "As" for Comparison: "She runs as fast as her brother." Cannot replace with "because," "since," or "for." Tips for Choosing the Right Word Use "because" for clarity in most situations. Use "since" or "

I think most sentences with this structure will work: "A because/since/for/as B". For example: They are often interchangeable, because they have an overlapping meaning. They are often interchangeable, since they have an overlapping meaning. They are often interchangeable, for they have an overlapping meaning. They are often interchangeable, as they have an overlapping meaning.

"Because" it is late, I must go. "Since" it is late, I must go. I must go, "for" it is late. I must go, "as" it is late. The meaning of all the sentences is the same. Sentence structure is slightly different. Good luck with studying English.