Dear Esl_Expert,
I appreciate your help and comments.
So whether the “because”-clause is a disjunct or an adjunct depends on the presence of the comma.
Quirk et al. (1985) would say that the “since”-clause in (3) is a content disjunct, which others call an “attitudinal” disjunct.
(3) Since she’s my friend, she must have put in a good word for me. (Quirk et al. 1985:1104)
Quirk et al. (1985) make no mention, however, of whether the conjunction “because” can also work as a content disjuct.
Do you think any of (4), (5a) and (5b) sounds natural?
(4) Because she’s my friend, she must have put in a good word for me.
(5) a. Because she’s my friend, [color=red]I think she must have put in a good word for me.
b. Because she's my friend, [color=red]I think she put in a good word for me.
My real interest is in something close to (5), but I don’t know where they belong in terms of Quirk et al.'s five categories of reason. (And as for (4), if this is OK, it will probably mean the “because”-clause is a content disjunct. If it is a style disjunct, you can’t put the “because”-clause before its main clause. And if it is an adjunct, the “because”-clause can be the focus of negation and interrogation, or the answer to the question beginning with “Why.” I assume (i) is wrong and instead we have to use (ii) in order that the conversation makes sense. So, if (4) works, the “because”-clause should be a content disjunct.)
(i) A: Why must she have put in a good word for you?
B: Because she’s my friend.
(ii) A: Why do you think she must have put in a good word for you?
B: Because she’s my friend.
Seiichi MYOGA
What is correct is that … Quirk et al. (1985:1104) say color=red and color=red are examples of “Reason and Consequence: the construction expresses the speaker’s inference of a connection.”
I apologize for confusion. I sent my previous post just before I went to bed. I always check my post before posting (and again immediately after that), but somehow I overlooked this.