Note: Edits in response to comments have been added in italics
The sentence prompting this question is:
Which I have always "loosely" taken to mean:
I am glad to hear you are doing so well these days.
Based on the explanation of と on page 464 of "A dictionary of intermediate Japanese Grammar", I think there is an ellipsis of 伺いまして, and hence is quotive but I am not entirely sure.
But to return to my question, when is 「だ／である」required between a noun and the quotation particle と?:
There some straight forward cases that are easy to remember such as (1)with names (2) direct quotes and (3)"fixed expressions" such as "とばかり”:
(1) Tim と言います| I am called Tim
(2)「＿＿＿＿」と言います。｜normal direct quote
(3)負けじとばかりゴールを目ざして走った｜Determined not to be beaten, he dashed toward the goal.
I also found the advice in the Dictionary of Basic Jpse Grammar that in the sentence:
米国の貿易赤字は しばらくのまま 続く もの と 予想される。 It is predicted that the US trade deficit will remain as it is for a while.
"Mono followed by a quotative と is used in general statements or opinion. This mono could be dropped without a change in meaning. Note that copula だ does not follow と."
But when making my own sentences of indirect quotes (etc?) it is not so straightforward because I am not sure what rule/principle applies.
Could somebody some insight on when the copula (だ）particle と go together?
(If sentence 3 is based on the same principle as sentence 2 then perhaps I have covered all the expceptions?)