In modern English I wish I were an optimist is correct.
Remember that was is the past tense. That sentence is talking about something that the subject is not, so it means: "I am not an optimist, but I wish I were."
No
There is a mistake in your bill.
You and your dad went to the store
I would have loved to meet your friend.
"If" makes it conditional, so "... what would you do?" would be proper.
The correct grammar is "Between you and me."
It is correct.
no_____If the sentence is You do do that (meaning You are in the habit of doing that) the grammar is perfectly correct and the sentence 'does have correct grammar'.
The correct sentence is: "Have you ever traveled before?"
This can fall under two different forms of sentence. One denoting a list, and one not. IE: Thomas is following Susanne. The following is a list of automobile parts you will need: So, this will largely depend on the kind of sentence you are forming and the information you are trying to get across to your audience.
No
was arrested
The correct grammar for the sentence is: "Please note that this letter is merely an inquiry regarding your interest and availability."
The correct grammar is "Here is some information." "Is" is used because "information" is an uncountable noun in this sentence.
There is a mistake in your bill.
The correct grammar for the sentence is: "During your vacation, did you stay in the hotel?"
The correct grammar for this sentence is: "When did you send it?"