Can we use "this is" as a main clause? And can an independent clause start with the word "then"?

Question

This is because they have already gone home.

In this sentence "because they have already gone home" is an dependent clause of independent clause "this is". Here my doubt is "this is" a main clause?

2.We went to the movie and then we went to restaurant near the theatre.

In this sentence "then we went to restaurant near the theatre" is an independent clause. Here my doubt is, can we start independent clause with "then"?

@BlackandWhite Not really. The main clause is This is because they have already gone home. The reason is that the because-phrase here is the complement of the verb be and therefore inside the main clause. However, if the sentence had been This is, because they have already gone home (notice the comma there) then the main clause would indeed have been This is and the because-string would have been an Adjunct. — Araucaria - Him, Sep 28 '17 at 15:15
This is can stand alone, though, as it's a complete independent clause. @Araucaria — , Sep 28 '17 at 15:19
@BillJ Well, they can if there is VP ellipsis. So for example: "What's the best beach cabin to use?" "This is, because they have already gone home". In that last sentence, "This is" is a main clause (embedded of course within the matrix clause). — Araucaria - Him, Sep 28 '17 at 15:21
Yes, if "this" is anaphoric and the complement if "be" is considered to be ellipted. — BillJ, Sep 28 '17 at 15:21
@Araucaria But I definitely don't say the subordinate clause is part of the main one. — , Sep 28 '17 at 15:23
@BlackandWhite Not in OP's sentence though, because the verb be there is taking the because phrase as a Complement. The sentence is incomplete without it. It's like if I walk up to you and say "Look at this! This is." That last sentence there isn't grammatical because the complement of the verb BE is missing. Does that make sense? In OP's example the bit that would be missing is because ...home. — Araucaria - Him, Sep 28 '17 at 15:24
@BlackandWhite Consider "I know you are busy". In that sentence I know isn't a main clause. That sentence has a matrix clause I know you are busy and embedded in that is the clause you are busy. But I know can't be considered a main clause because it isn't complete! See what I mean? — Araucaria - Him, Sep 28 '17 at 15:29
It is complete, though. Why wouldn't it be? Subject plus verb. Also, thanks for your patience with me! @Araucaria — , Sep 28 '17 at 15:36
@BlackandWhite I'm not being patient, I'm just appreciating chatting about linguiticky things with you:) The reason I don't think it's complete, is because verbs (and other words too) kind of set up slots for other phrases. So, for example, the verb PUT sets up spaces for a person/thing that moves something, a thing that's moved, and a destination for that thing. If one of those is missing, then the clause isn't complete. Consider Puts the pen outside (no person putting). She put the pen (no destination). She put outside (no thing that's moved). Now, some special verbs allow you ... — Araucaria - Him, Sep 28 '17 at 20:43
@BlackandWhite ... to miss stuff out if it's already been mentioned. So for example in A: "Remember to put the cat out" B: "I will!" - the verb WILL allows you to miss out the rest of the verb phrase put the cat out. But the point here is that that's only OK if there's already something to miss out. If there isn't, the clause won't work. In the OP sentence, the string This is* is only a full grammatical clause because the verb BE is taking because ... home as a Complement ... — Araucaria - Him, Sep 28 '17 at 20:52
@BlackandWhite ... If the verb BE had a "left out" Complement, then there would be a comma after is, because that would be the end of that clause. Here the rest of the clause is filling the special space set up by is. — Araucaria - Him, Sep 28 '17 at 20:52
Broadly, no. … this is as a main clause would depend on the context, wouldn't it?
Alone, This is because they have already gone home means nothing; it’s not even grammatical.

In Blah lah lah blah. This is because they have already gone home, what exactly does This is… contribute that justifies it’s being a main anything, please?

Meanwhile, would you mind separating those rather different subjects into two different questions, please? — Robbie Goodwin, Sep 29 '17 at 20:48

score 2 · Answer 1 · answered Sep 28 '17 at 15:49

2

In the sentence "This is because they have already gone gone home," the main clause is indeed "This is" with an implicit complement of "true" or "correct." The "this" is being used as a substantive representing something said previously.

"This is because Y" means "[The previous statement] is [true] because Y." No native speaker will wince at "This is because Y."

Although it is grammatical, it is very informal and wordy in style. I would be very unlikely to write (except as realistic dialogue)

"X. This is because Y."

Instead I would be likely to write

"X because Y." But people do not necessarily speak in the way that they should write.

As for the second question, where A and B are independent clauses

"A and then B" is not punctuated as I would like, but "A, and then B" is perfectly proper English. "Then" is being used to indicate a temporal sequence.

answered Sep 28 '17 at 15:49

Jeff Morrow

1,470

We went to the movie and then we went to restaurant near the theatre. "Then,now, and after" all here are adverbs. All adverbs that can tell us when we can be placed at the beginning of the sentence to emphasize the time element. Am I right? – nanu1 Sep 29 '17 at 04:37
But because ... home is a Complement of the verb here. So it is inside the clause headed by is, and the clause with is is ungrammatical without it. Therefore this is is not a main clause. – Araucaria - Him Sep 29 '17 at 13:39
This is a good illustration of the grammar of spoken English. This is because written formal English differs from what people actually say. "This is" followed by a clause introduced by when, because, why, how, what, etc. are very common in speech. And I would not get my knickers in a twist over this form. – Lambie Jun 27 '18 at 17:35

score 0 · Answer 2 · answered Jun 27 '18 at 17:13

Sentence 1 is a perfectly good and grammatical sentence. It's evidently an explanation of some sort, but, since it is alone, we don't know what it is explaining. It ought to follow some other sentence, such as "They're no longer at the party." [But that's not what the OP asked about.]

Sentence 2 is also a perfectly good and grammatical sentence. To answer the accompanying question, yes, of course you can begin an independent clause with "then" (which in this case has the meaning of "subsequently").

Can we use "this is" as a main clause? And can an independent clause start with the word "then"?

2 Answers2