Forecast

[RonPurewal]

Dear Ron or Tim,

I'm confused why "I have higher bills than last year" is right(From Manhattan 6th edition page 101 )

^^ shouldn't be ok.
it's ok to write "i have higher bills this year than last (year)". note, in particular, that the two things flanking "than" are of the same type (both are timeframes).

i'll point this out.

and "They have to know more than now“ is wrong (from OG 42)

^^ not comparing similar entities.

[RonPurewal]

Please help judge if the following sentences or understandings are correct.
sentence 1: They have to know more than they do now.
sentence 2: They have to know more than they know now.
sentence 3: They have to know more than now.
sentence 4: They will know more than now.

my judgement is : right,right,wrong,right. Am I right?

this is not how you should approach comparison problems.

ALWAYS regard comparison problems as "beauty contests" -- in other words, as competitions among answer choices.

DO NOT try to learn how to write every possible kind of comparison sentence from scratch!
• first of all, writing proper comparison sentences is very, very, VERY hard. it takes the skill of an accomplished writer, and largely transcends the skills of just about everyone else -- including the vast majority of native english speakers.
• ...and, more to the point, it's completely unnecessary, since no one is ever going to run up behind you and steal the multiple-choice answer options.

[RonPurewal]

e.g.,

in the problem to which you're alluding, you have a "beauty contest" between
...have to know more than now
and
...have to know more than they do now.

this decision is VERY straightforward.

• first, the latter has two similar things flanking "more than", while the former does not.

• second, the latter sentence is more explicitly clear about the transition between timeframes/tenses.

[RonPurewal]

analogy:

• solving one of these multiple-choice problems is like looking at two robots and asking yourself, "which one walks more like a human?"

• trying to WRITE these sentences (or, equivalently, trying to judge whether they are INDIVIDUALLY right or wrong) is like trying to DESIGN a robot that walks like a human.

these tasks are in entirely different leagues, of course. there's no sense in attempting the second if you're only responsible for the first.

[GeorgiaF924]

Thank you soooo much, Ron! You not only solve my problem perfectly, but also correct my way to study SC problems.
Your vivid examples always make things easy to understand. No wonder everyone says you are the best teacher!

[RonPurewal]

well, thanks -- although "everyone" is a bit over the top (i have a style that works for some students, but maybe not for others ... just like anyone else who teaches, well, anything.)

in any case, i'm glad you're deriving value from the discussions here, and i'm also glad you've taken the time to say so. thanks.

[thanghnvn]

source GMATPrep

To develop more accurate population forecasts, demographers have to know a great deal more than now about the social and economic determinants of fertility.

A. have to know a great deal more than now about the social and economic
B. have to know a great deal more than they do now about the social and economical
C. would have to know a great deal more than they do now about the social and economical
D. would have to know a great deal more than they do now about the social and economic
E. would have to know a great deal more than now about the social and economic

OA = D...can someone please tell what is wrong with A and E ?

in many other sc question, Than now , is ok but "than now" is not ok in this problem because we have no "yesterday" or "last year" in the first part of comparison

I think og book accepat the following
last year, I worked more than now

so, this problem is not simple

[BOw541]

don't forget the difference between "economic" and "economical", which is huge.
"economic" means "having to do with "economics and/or the economy". (this is the intended meaning.)
"economical" means "efficient" or "at low cost/expense". (this is not the intended meaning.)

i think this sentence makes sense with either "would have to" or "have to". there's a slight rhetorical difference ("would have to" carries the connotation that these forecasts are just hypothetical and don't actually have to be developed, or that at least it's not important, while "have to" implies that these forecasts are important and have to be made), but you don't have to make such rhetorical distinctions on the exam.
in this case, you don't have to, since both choices involving "have to" (without "would") are wrong for other reasons.

(a) is only wrong for the reason mentioned by the poster above me.

Hi Ron,
I made up this sentence:
The quality of food is better than (The quality of food) ever.
Is this correct?

[RonPurewal]

WITHOUT the stuff in parentheses it's fine.
this sort of comparison is idiomatic. it's like more than usual. i wrote about this here:
https://www.manhattanprep.com/gmat/foru ... 30267.html

WITH the stuff in parentheses it's wrong, but the reasons are irrelevant here (the exam has never tested any faulty comparison with such a form).

[JustinCKN]

Dear Ron or Tim,

I'm confused why "I have higher bills than last year" is right(From Manhattan 6th edition page 101 )

^^ shouldn't be ok.
it's ok to write "i have higher bills this year than last (year)". note, in particular, that the two things flanking "than" are of the same type (both are timeframes).

Hi Ron:
You say: it is ok to write "I have higher bills this year than last year."
May I comprehend that in this way: " I have higher bills this year than ( I had) last year.
But the omitted part ( I had) is in the different time frame as its parallel counterpart ( I haver higher bills ).

According to your analysis " if you omit the verb, the omitted verb will be assumed to be in the same tense as its parallel counterpart".
the sentence "I have higher bills this year than last year“ should be incorrect.
What is wrong with my though ? Please show me the light.
Thanks advanced.
Sincerely
JustinCKN.

[RonPurewal]

don't think about "omitted words".
https://www.manhattanprep.com/gmat/foru ... ml#p113659

[JustinCKN]

2/
It's a helping verb. It implies "have ___ed", parallel to some verb on the other side.
I am now making more money than I ever have before.
(= "have made")

DEAR Ron:
According to your other thread, I think that the sentence above should be written like this:
I am now making more money than I ever have MADE before.
Since "have" in the second part of parallel structure is in Present Perfect tense, If we want to omit the word " made" ,we should also need a corresponding form of "have" in the first part.
But in the first part we do not have a corresponding form of "have" , therefore we need the "MADE" after "than I ever have _ before.“

My thought comes from another thread written by you,https://www.manhattanprep.com/gmat/forums/since-1990-the-global-economy-has-grown-more-than-it-did-t552-15.html
"Since 1990 the global economy has grown more than it did during the 10,000 years from the beginning of agriculture to 1950. "

note that this sentence fits the third form given in that post -- "did" is a form of "to do", and "has grown" is a tense of the action verb "grow" (it's called the "present perfect tense", if you like to name these things)

notice that the reverse of this kind of structure would not be permissible; if you had just "has" as the second part of the parallel structure, then that's no longer the present perfect tense of an action verb, and so in that case you would also need a corresponding form of "have" in the first part.

Thanks!
Sincerely.
JustinCKN.

[RonPurewal]

please read point #2 here again.
https://www.manhattanprep.com/gmat/foru ... ml#p113659

[jabgt]

well, thanks -- although "everyone" is a bit over the top (i have a style that works for some students, but maybe not for others ... just like anyone else who teaches, well, anything.)

in any case, i'm glad you're deriving value from the discussions here, and i'm also glad you've taken the time to say so. thanks.

Oh, Ron Sir, I have always thought that you have been receiving tons of thank-you notes each single day, so I refrain myself quite hard from repetitively expressing my gratitude to you, sending actually fewer than 1% I'd have liked to. I believe many many many people share this idea with me.

For example, I guess addressing you by name+Sir sounds ridiculous to native English speakers, but I just want to pay my high respect to you. (Because I found Jon Stewart occasionally addressed his most honored guests "Sir" to welcome them in his daily show.)

[RonPurewal]

thank you, i appreciate all that.

it's true that name+"sir" is not a normal form of address in north america, but, i understand what you're doing there (...and, thanks!).