aspect(perfective or imperfective)
67182
reference time,situation time
78336
past simple or present perfect
13349
"Subject, verb, direct object, object complement" versus "subject, verb, indirect object, direct object"
34145
Perfect infinitive
137568
Confusion using articles (A ,an ,the)
64988
Verb/Subject Agreement Make/Makes
25213
Analysing the "kind(s) of problem(s) are [ones]/[to be]" construction
114989
The logic behind present perfect/infinitive + present perfect
131090
On the singular vs plural aspects of "who"
23041
Why: a relative adverb, a conjunction ... or both?
86883
Subject + am/is/are + to + verb
157993
The case of an object of a preposition
139726
differentiating between the usages of "seem"
92634
Those vs They vs That
47662
Present perfect for past action with present effect
151248
Extraposed clauses
110521
Preventative vs. preventive