NDA (II) 2016 GAT Q43: I have been waiting here for the last two

Q: What is the answer to NDA (II) 2016 GAT Q43?

D. Correct — D, NO IMPROVEMENT. 'The last two hours' names a stretch of time rather than a moment, and English marks a stretch with 'for', so the sentence as printed is already right — 'I have been waiting here for the last two hours.'

NDA (II) 2016 General Ability Test · Question 43 of 150

Question text verified against the official NDA question paper.

I have been waiting here for the last two hours.

(a)from
(b)since
(c)by
(d)NO IMPROVEMENT

Answer

Why

Correct — D, NO IMPROVEMENT. 'The last two hours' names a stretch of time rather than a moment, and English marks a stretch with 'for', so the sentence as printed is already right — 'I have been waiting here for the last two hours.'

Why the others are wrong

(a)from — 'From' announces a starting point and normally expects a matching 'to' or 'till'; it is not used with a perfect tense to measure how long something has gone on.
(b)since — 'Since' has to be followed by the point at which the period began, such as 'since four o'clock' or 'since Monday', not by the length of the period.
(c)by — 'By' fixes a deadline — 'by six o'clock' — and says nothing about duration, so it cannot govern 'the last two hours'.

Concept

'For' measures how long a period lasted; 'since' names the moment it started.

Every option here is a preposition of time, so the item is really a single question asked four ways — does 'the last two hours' name a length or a moment. It names a length, and that settles it in one step. Items of this kind are also a reminder that in a sentence-improvement set the printed sentence is sometimes already correct, and a candidate who assumes there must be a fault will change a right answer into a wrong one.

Key facts

'For two hours' states a duration; 'since two o'clock' states a starting point.
The present perfect continuous is the usual tense for an action that began earlier and is still going on.

Study next

Prepositions of time — for, since, from, by, till and untilThe present perfect and present perfect continuous with time expressionsRecognising sentence-improvement items that need no change at all

Common traps

Assuming that the underlined part must be faulty because it has been underlined.
Using 'since' before a length of time instead of before a point in time.

Asked as a sentence-improvement item on time prepositions, with a correct sentence and three plausible-looking substitutions.

Related PYQs

NDA_GAT_2017_II_Q462017Open & attempt →

Years _____ since I saw her last.

(a) have passed
(b) had passed
(c) had been passing
(d) have been passing

Answer(a) have passed

The same family of time expressions. That NDA item turns on what tense 'since' pulls after it once a starting point has been named; this one turns on the choice between 'since' and 'for' when the time expression is a length rather than a point.

Practice

practice — not a real PYQ
Which option best improves the underlined part — She has been unwell since the last three days.
- (a)for
- (b)from
- (c)by
- (d)No improvement
Answer(a) for — 'the last three days' is a length of time, so it takes 'for'.
practice — not a real PYQ
Which option best improves the underlined part — They have been living in Pune for 2010.
- (a)since
- (b)from
- (c)by
- (d)No improvement
Answer(a) since — a year names the point at which the period began.