Yes, "best possible" is correct grammar, as in this sentence:
This is the best possible outcome considering the circumstances.
"When is the best time I can call you?" is correct.
This is a correct grammar. But it is no possible to cash someone else's SS check.
Grammar is tricky. If you did not learn it as a child, the best way to learn it (and know whether your grammar is correct) is to find someone who speaks correct grammar and listen to them, a lot. NPR is a good place to listen to people who have good grammar.
"On a train" is correct grammar.
Grammar.
Both are possible and correct.
"When is the best time I can call you?" is correct.
I have worked with my mentor and responded to the customer
The sentence "It lacks agreement Possible correct alternatives are He is the one of the men who does the work or He is one of the men who do the work" are not of correct grammar.
You were - This is correct. You were the best in the team.
Yes, that is a grammatically correct phrase. You might use it as follows: I answer questions as well as possible.
This is a correct grammar. But it is no possible to cash someone else's SS check.
No, "will be had" is not a correct grammar. The correct grammar would be "will have."
Grammar is tricky. If you did not learn it as a child, the best way to learn it (and know whether your grammar is correct) is to find someone who speaks correct grammar and listen to them, a lot. NPR is a good place to listen to people who have good grammar.
No, it is correct grammar, not a correct grammar.
The correct grammar is: "Are those correct?"
"On a train" is correct grammar.