Will the placement of two conjunctions that appear consecutively sound better?

Question

I found this sentence from my exercise book (Oxford Grammar):

I felt lazy, and because I didn't have any real work to do, I took the afternoon off.

The execise instructs me to guess whether it's correct or not. The key answer is correct, but I have a question. Why isn't this sentence written like this:

Because I felt lazy and I didn't have any real work to do, I took the afternoon off.

Which one is more grammatical? If there's none, please provide your version. The reason I think the first sentence above seems to be weird is because and and because are placed together consecutively. In my opinion, it has the structure:

《Main clause/stand-alone sentence》 + 《conjunction》 + 《complex sentence (subordinate + main clause)》.

Again, in my view, would it sound better if the structure is written like this:

《Subordinate clause》 + 《Main clause》

Where the subordinate clause in my version carries equal-weight clause.

Answer 1

I think you're analyzing a little harder than the exercise meant for you to. Commas often work in pairs to "set off" phrases, and you can often check grammaticality by deleting those phrases.

• "I felt lazy I took the afternoon off" is not valid.
• "I felt lazy and I took the afternoon off" is, so we should include the "and" in the first phrase, not use a comma to move it into the second phrase.
• "I felt lazy and, because I didn't have any real work to do, I took the afternoon off." The previous sentence is still here; we've just added a bit more explaining information. The extra phrase, "because I didn't have any real work to do," could be deleted without invalidating the sentence, so it gets set off with commas.

Sure, one could rewrite this sentence with a different word order, but it sounds like that isn't the focus of the exercise. And stangdon is right; although in this case, logic does suggest that "I felt lazy" is another of the reasons to take time off, the structure doesn't always work that way.

It was noon and, because I didn't have any real work to do, I took the afternoon off.

In this case, the time being noon isn't one of the reasons I took time off.

But of course, you could rewrite all these sentences by moving the "because" clause to the end and you could use no commas at all (though you might want some optional ones for clarity).