before those have/are???

[zeeman]

In general, the simpler plants appeared on the Earth before those ________.

(a)are structurally complicated
(b)more complicated in structure
(c)have a complicated structure
(d)their structure is complicated

Which is the right answer,why?

[Erin]

B is the right answer; it's a reduced adjective clause. The original clause would be:

that are more complicated in structure.

If you got confused, you were probably thinking that 'before' could be followed by a sentence, in which case A, C, and D would all be correct. However, we need to remember one thing:

before is one of six words that can be followed either by a noun only or by a sentence. In other words, there are six words that can function as prepositions or as subordinating conjunctions.

Now, if before is a subordinating conjunction in this case, then those must be the subject. However, those cannot be the subject since it has no referent; if we want to refer to plants, we would need to use they, not those.

So, in this case, before cannot be followed by a sentence; it must be followed by a noun only.

It might also be helpful to know that we often use such a pattern in English, like this:

those + adjective clause

For example:

• Success comes to those who give the most happiness to others.
• Those who are interested in attending the party should be sure to tell Kathy.

This sentence has so many different things going on at one time, so it's hard to explain everything right here, but if you have a specific question about anything I've said here, please post back under this thread, and I'll answer!

Hope that helps.

[zeeman]

Thank you very much,Erin.

[kmokang]

Thanks, I got it!

Then, when can these(with referent) is used?

[Erin]

Do you mean "those"? Or "these"? I assume you mean "those".

The answer to this is a bit tricky, but in general, "those" refers to people or things, but we sometimes use it in comparisons as well.

Look at these examples:

Those hoping to raise their TOEFL scores without any study might well be disappointed.

Those schools not conforming to current regulations will be closed.

This question has so many exceptions, etc., that I'd have to ask you to post an example for me to explain.

HTH

[meteor]

Originally Posted by Erin

before is one of six words that can be followed either by a noun only or by a sentence. In other words, there are six words that can function as prepositions or as subordinating conjunctions.

Hi Erin,
Could you tell me the name of these six words.
Thanks a lot.

[haohmaku]

Erin, I think he want to ask you whether we can use these instead of those.

[paltrow]

erin ı would like to know 6 other wds as well if it is possible could u tell.

Success comes to those who give the most happiness to others.

And I also wonder that ''those'' in here doesnt refer a people so iit can be referent... or I misunderstood.

thank u erin...

[Erin]

Originally Posted by meteor

Hi Erin,
Could you tell me the name of these six words.
Thanks a lot.

They don't have a name, as far as I know.

The words are as, since, until, before, after, and for.

Erin, I think he want to ask you whether we can use these instead of those.

Nope, not in that example.