Sentence Correction

adi_800 wrote:Aha....Totally confused...
Ron... I hope you reply to my first post to you...:)
Appear (Or Appears ) -> Present tense...
Appear is parallel to indicates, which is in present tense... So appear is also in present tense..

well, yeah, but this depends on what sort of parallelism you are talking about.

important note:
GRAMMATICAL parallelism has NOTHING to do with the tenses of verbs. only CONTEXT determines the proper tense of a verb.

here's what i mean.
consider the following sentence:
i have won all of the games played so far, and will win all of the remaining games.

notice that this sentence contains a parallel structure -- "i VERB and VERB" -- and that it's a perfectly correct sentence.

the point here is that the verbs don't have to be in the same tense just because they are in a parallel structure. the only requirement of grammatical parallelism is this: if one of the structures is a VERB, then the other structure must also be a VERB.

as is always the case, the tenses of these verbs are determined entirely by the context of the sentence. the first verb is in the present perfect because it refers to a pattern that has persisted until the present moment, while the second verb is in the future tense because it describes a future action.

--

so, you may or may not be correct, depending on what you meant when you said "parallel".

if you meant that the tenses should automatically be the same just because these constructions are grammatically parallel, then, no, that's wrong.
on the other hand, if you were (correctly) observing that the two CONTEXTS are "parallel" in terms of simultaneity, then that's absolutely correct -- both parts refer to observations made in the present -- and that's why the tenses should be the same.

But when appear paired with to have been equipped (appear to have been equipped) gives you a action in past tense...
N the context of the sentence demands a past tense....So that's why we are using a past tense here....

i meant exactly what i wrote -- you can't really boil this down to one timeframe.
* "appear" is in the present tense, because the observations are made in the present.
* on the other hand, "to have been equipped" is written in a way that suggests a past situation. (if this were still the case in the present, it'd be "to BE equipped".)

both are important.

Also is appear as equipped is present tense??

well, sure, although that construction ("appear as ADJ/DESCRIPTION") is idiomatically wrong no matter what tense it's in.

duongthang wrote:Ron, member, pls, help.

in many questions in OG books, I see that whenever questions make us choose between "for doing" and "to do", "to do" is correct.

In general grammar,there is no dicussion of "for doing"/"to do". So, I think that this point is regulated by gmat grammar, not general grammar. In short, gmat grammar declare that "to do" is correct and "for doing" is incorrect.

Is my thinking correct? pls, help .

your thinking is not correct. the reason you don't see these pieces mentioned in books is that they are just pieces of constructions -- i.e., they are not complete constructions, and you can't decide how to use them in isolation.
in other words, the choice between "for doing" and "to do" relies on the surrounding context.

if they are part of a parallel structure, then you need to choose the form that is parallel to the other part:
e.g.
this computer terminal is more useful for playing games than for doing homework --> correct. you wouldn't want "to do" here, because that wouldn't be parallel to "for playing".

also, if they are being used within some idiom, then you need to choose the version that is idiomatically correct (although, according to the recent GMAC announcement, this knowledge is now much less important).

duongthang wrote:Ron, Thank you. in the previous post you write

it seems that the students cheated on the xam

students seem to have cheated on the exam.

are two similar ideas.

what is the difference between

students seem /appear to have cheated on the exam

and

students SEEMED/APPEARED to have cheated on the exam.

in the first, "have cheated" refer to a part action. In the second "have cheated" refer to what.

"to have VERBed" is a type of infinitive that refers to actions in a timeframe previous to the timeframe of the sentence itself. this is actually the only kind of infinitive that can do this, so it will take the same form regardless of the tense of the main clause.

so, if you write
"the students seem to have cheated"
then
* the sentence itself is in the present ("seem"). so, the sentence is talking about the way things appear to a present observer.
* according to that present observer, it seems to be the case that the students cheated at some point in the past.


if you write
"the students seemed to have cheated"
then
* the sentence itself is in the past ("seemed"). so, the sentence is talking about the way things appeared to a past observer.
* according to that past observer, it seems to be the case that the students cheated at some point earlier in the past.