Future Tense in Past Tense

[Maybells]

In English, if you are speaking in the past tense and are describing something that was a future event in the past, you use a construction like "it was going to rain" or "little did I know it, but things were going to get much worse".

I know that in Latin you can use a periphrastic with the future participle like "visurus eram", but does that construction also appear in Greek ("ὀψόμενος ἦν"?) or would it be said some other way?

[bedwere]

Here is a comparison of Latin and Greek periphrastic tenses

Instead of the Greek future participle, you could use μέλλω + infinitive

[jeidsath]

From the Cambridge Grammar 52.4:

The future participle always has a relative-tense interpretation, referring to an action posterior to that of the matrix verb:

(12) οὐδέπω . . . δῆλος ἦν . . . ἐκεῖνος τοιαῦτα γράψων. (Dem. 19.236)
It was not yet clear that that man was going to draft such proposals.

Also see 52.41, "the future participle usually expresses purpose." It mentions the idiomatic expressions ἔρχομαι + fut. ppl. "be about to, be going to", especially with participles of verbs of speech.

ἐγὼ δὲ περὶ μὲν τούτων οὐκ ἔρχομαι ἐρέων ὡς . . . (Hdt. 1.5.3)
I am not going to say about these things, that . . .