Yes, there is a distinction between "because" and "because of" in terms of their usage in sentences.
"Because":
"Because" is a subordinating conjunction used to introduce a reason or cause. It typically introduces a subordinate clause.
Example: "She stayed home because she was feeling sick."
"Because of":
"Because of" is a prepositional phrase used to indicate the reason or cause of something. It is followed by a noun, pronoun, or noun phrase.
Example: "She stayed home because of her illness."
Here's a general guideline to help you decide when to use each:
Use "because" when the reason is a complete clause (i.e., it has a subject and a verb).
Use "because of" when the reason is a noun or a noun phrase.
However, there are exceptions and nuances in usage. For instance:
In casual speech, people often use "because" in situations where "because of" would technically be more grammatically correct, but the meaning is still clear and understood.
There might be instances where "because of" is followed by a clause, especially in formal writing, but it's less common.
In summary, while there's a guideline to distinguish between the two, context and register can influence their usage.