请教大家一个to do用法的问题 - ChaseDream

“用不定式位于句尾，使用逗号与前句隔开――这种结构是一种错误的结构。”

是不是少了一个“不”字。。。
斑竹大人到，问题都解决~
我倒是觉得这个问题没有那么绝对，就像斑竹大人所说，其实还要看逻辑和通顺的问题。。。

-- by 会员 pennyconan (2010/5/5 10:43:42)

再补充个句子：
大全473. Lawmakers are examining measures that would require banks to disclose all fees and account requirements in writing, to providefree cashing of government checks, and to create basic savings accounts that carry minimal fees and require minimal initial deposits.
-- by 会员 aeoluseros (2010/5/5 10:49:56)

For members of the seventeenth-century Ashanti nation in Africa, animal-hide shields with wooden frames were essential items of military equipment, a method to protect warriors against enemy arrows and spears.
E to protect
OG的解释是：Choice E is incomplete; used to protect would have been acceptable.
这里to do的形式incomplete就是因为，to protect在这里是表示目的的，表示目的的不定式不可以单独出现在逗号后面。如果加上used就可以接受了。
正确的是protecting

OG上找到两个例子：
OG10-34的explanation Choices C and D are needlessly wordy, and D requires that before North Americans, to be grammatically complete.

这个例子来自解释，而不是原题。

185. The recent surge in the number of airplane flights has clogged the nation's air-traffic control system, to lead to 55 percent more delays at airports, and prompts fears among some officials that safety is being compromised.

(A)to lead to 55 percent more delays at airports, and prompts

(B)leading to 55 percent more delay at airports and prompting

(C)to lead to a 55 percent increase in delay at airports and prompt

(D)to lead to an increase of 55 percent in delaysat airports, and prompted

(E)leading to a 55-percent increase in delays atairports and prompting

OG10的解释：
This question poses two major problems: parallel structure and precision of expression. In E, the best choice, parallel structure is maintained in the participial phrases introduced by leading and prompting, and the phrase 55-percent increase in delays conveys the meaning more accurately than does the phrase 55 percent more delay(s) in A and B. Also, choice A lacks parallelism. In C and D the infinitive phrase to lead to ... is less idiomatic than the participial phrase leading to .. .'_ Choice C uses the singular delay where the plural is needed to indicate an increase in the number of delays; the phrase increase in delay has no exact meaning.

OG11、12的解释：

Parallelism + Diction

The intent of the sentence is to show two effects of the surge in flights. These effects should be stated in parallel ways, instead of the construction to lead ... and prompts ... used in the original sentence. Using participial phrases introduced by leading and prompting solves this problem. The phrase 55 percent more delays is not as clear as the phrase a 55 percent increase in delays.

ATo lead and prompts are not parallel; 55 percent more delays is not clear

B55 percent more delay is unclear

CTo lead and prompt are not parallel; the meaning of increase in delay is not clear

DA participial phrase introduced by leading is preferable to the unclear infinitive phrase to lead to; an increase of 55 percent in delays is awkward and wordy

ECorrect. Leading and prompting are parallel in this sentence; the phrase a 55 percent increase in delays is clear
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OG里并没有说to do不可以用，只是说了unclear, unidiomatic，而对于leading也只说了preferable，说明语法上leading和to do都可以，只是用了infinitive phrase造成了含义上的unclear。

不知道这下能否下结论了。但我更为相信“不定式可以在句尾做单独结构”。因为不能在句尾做单独结构并没有很合理的解释，只是当初XDF还是刘振民说出的一个观点，并没有说明本质的evidence。

-- by 会员 aeoluseros (2010/5/6 9:46:15)

我推测，主系表的系动词不是be的时候，用逗号加ving就不适合理解成定语，因为这个时候理解成定语还是状语句意大不相同。

-- by 会员抓抓sandra (2011/8/20 7:55:03)