Are there any differences between "I am sure" and "I was sure"?
98159
Reported / indirect speech - why no backshift
63768
Difference between "OK" and "okay"
83884
"So am I" or "So do I"?
74060
Is "You are correct" correct?
87312
Using 'is' or 'was' when something is still true
103135
What's the error in "Either he or I is right"?
87651
I'm being corrected "I had a headache yesterday" vs "I have had a headache yesterday"
5498
What's the difference between "should" and "could" (in the present tense)?
70600
“What I saw was…” vs “What I saw were…”
148617
If something was vs If something were
82701
I lived Vs. I was living
6938
"I believe it's valid" vs. "I believe it valid"
109074
"You are" vs. "you're" — what is the difference between them?
108316
Why is "He said me he was ..." ungrammatical, but "He told me he was ..." is not?
141279
Is there a difference between  and ?
69421
Which tense after 'would I... if.... ?'
17238
Is "aren't I" correct grammar?