1. You did a hell of a job keeping it [color=red]secret all these years.

  2. You did a hell of a job keeping it [color=red]a secret all these years.


Which one is corect?


They are both possible. In the first case “secret” is an adjective. In the second case it is a noun.

But wouldn’t we have to use “as a secret” in the second sentence?

‘keep a secret’ is idiomatic.

Tom: (Blah…)

Jerry: Tom!

Tom: But I digress([color=red]Or digressed?). You know…


Which tense should we choose here? Present or past?


There’s not enough context to tell, because both are possible.

Jerry is asking Tom to tell him something. Tom starts to do it but digresses to another subject. Then Jerry reminds him and after saying the phrase, Tom comes back to the original subject.

As it’s happening in the present, then he probably says ‘I digress’.
However, if he means that a very short while earlier he went off the subject then he could just as easily and correctly say ‘I digressed’.