Why is using "have" or "have had" necessary?
12310
When is the present perfect tense used instead of the past tense?
22092
Why do we use 'did' with questions using the simple past tense?
32288
'Country have' vs 'country has'
12613
How to use "had" correctly in a past perfect paragraph?
137281
"Has" or "Have" with "Each"?
68478
The use of "were- should- had” at the beginning of sentences instead of “if”
121488
Why do we use "have" with does and not "has"?
508
"Have been doing" and "have done"
72276
Have gone or Have been
92516
"Might have" vs "could have"
4548
“have found” vs. “found”
73018
To tell about a guess about a case in the past, why use "would+have+past participle" instead of "must+have+past participle?
37239
What does "had had" mean? How does this differ from "had"?
136798
Plural followed by singular - "have" or "has"?
127529
Correct use of "is having"
95961
When should I use "Would",  "Would have", "Will", and "Will have"?
154084
Having done something,... vs Doing something,