The MOST effective would be,
(Check surrounding words) and
(Substitute the unfamiliar word with a familiar word)
The Stage Manager overlaps past and future when he describes the Gibbs:
"Doc Gibbs died in 1930." (future) Then he says: "Mrs. Gibbs died first--long time ago, in fact." (past).
The second example is when he talks about the cornerstone they're putting in the bank so that people "a thousand years from now" can find it. He discusses the ancient Babylonians and then the people of a thousand years from the present.