object

[Eddie88]

They join related thoughts, rather than separating them, which makes the link between the two sentences less obvious.


They join related thoughts, rather than separate them.


This sounds right also. It's a compound predicate (join and separate), and rather than is a preposition functioning as an adjective...


However, can 'separate' work here? The object of a preposition needs to be a noun..

[OddThomas]

First, rather than is a conjunction in this usage, not a preposition. Consider your point that you have a compound predicate: the link must be a conjunction, not a preposition.

Second, separate must be grammatically parallel to join (tense, aspect, etc.) to be properly compound. They join related thoughts, rather than separate them, is the correct verb for this sentence, as you showed (unwittingly, I suspect :)).

The improved sentence is:They join related thoughts rather than separate them, which makes the link between the two sentences less obvious.
I removed the comma because rather than does not start a new clause, and I don't like separating simple compounds (personal punctuation bias).

[Eddie88]

What you have said makes sense. I was misinformed earlier; I was told 'rather than' was a preposition, which is the reason for my confusion.


Though the parrallel version is probably preferable, the ing form can be used to create variety. For instance,

an ing form is often produced simply by changing the second verb in a compound predicate to its ing form.


With regard to the punctuation, I agree. Commas shouldn't join a compound predicate unless one is lengthy.


Thanks for helping me realise that this is in fact a conjunction.

[OddThomas]

I agree that verb form may change for variety (this license is available to the skillful writer), yet separating is not a verb. Try removing the former of the two predicates and observe the effect:They join related thoughts rather than separating them, which makes the link between the two sentences less obvious.
While separating rolls off the tongue easily, this alone is not enough to redeem its ungrammaticality.

In a compound predicate using a coordinating conjunction such as yet, we might have:They join related thoughts yet are not separating them, which makes the link between the two sentences less obvious.
In the above example, join and are separating are both present tense, and their aspects differ for variety (as you suggest). While not rigorously parallel, this structure should present no style or usage problems.

.
Rather than can be a preposition--many conjunctions have an element of preposition to them, and the distinction is not always obvious.They join related thoughts rather than disjoint thoughts, which makes the link between the two sentences less obvious.
In the above (nonsense) sentence, rather than is a preposition. Notice the nominal immediately following rather than, thereby becoming the object of the preposition.

[Eddie88]

They join related thoughts yet are not separating them, which makes the link between the two sentences less obvious.In the above example, join and are separating are both present tense, and their aspects differ for variety (as you suggest). While not rigorously parallel, this structure should present no style or usage problems.
When I said I was changing the second verb to an ing, I was also stating that the form changes, from a compound predicate to a single predicate with a participle phrase. This, therefore, is slightly different from what you have discussed above; Yours has kept the auxiliary 'are' and has a preceding conjunction, while I was meaning the sentence would look like this:

They join related thoughts, not separating them, which makes the link between the two sentences less obvious.

Here is another example:

I ran home and thought about what I had just done.

I ran home, thinking about what I had just done.

Or

I ran over the try-line and placed the ball under the posts.

I ran over the try-line, placing the ball under the posts.

[Eddie88]

Rather than can be a preposition--many conjunctions have an element of preposition to them, and the distinction is not always obvious.
They join related thoughts rather than disjoint thoughts, which makes the link between the two sentences less obvious.
In the above (nonsense) sentence, rather than is a preposition. Notice the nominal immediately following rather than, thereby becoming the object of the preposition.


I had thought about determining whether a conjunction was in fact a preposition by identifying the part of speech after the word(s). However, I realised this cannot be full proof, because if the word following the prep or conj is a noun, it could be a conjunction joining two noun phrases, not a prep with an object.

What do you think about this?

Cheers
Edd

[OddThomas]

You are right that being a noun is not diagnostic (it is not sufficient to prove the case). I said "notice the nominal" as a solid hint that we had a preposition at work here. Our noun stands in contrast to the predicate on the other side of rather than, eliminating the possibility of conjunction.

[Eddie88]

You are right that being a noun is not diagnostic (it is not sufficient to prove the case). I said "notice the nominal" as a solid hint that we had a preposition at work here. Our noun stands in contrast to the predicate on the other side of rather than, eliminating the possibility of conjunction.


I think you have them the wrong way around. You mean "eliminating the possiblity of a preposition"

Correct?