Tatiana: MAKE IT and COME both express "arrival" - MAKE IT = arrival on time, COME = general arrival. So you can't have them both! :)

This post sounds weird to me in both language. In what context would it be used in Russian?

For example, when we said we would come to the party or go on an excursion etc. and everybody expected us to come but then the circumstances changed at the last moment and we didn't come. And later our friends asked us, why we hadn't warned we wouldn't come.

Разговорный вариант предложения: Я не могла предположить, что мы не сможем прийти.

I couldn't know we couldn't make it.?

I didn't know we weren't going to make it.

+Elena

Ули, we weren't going to do - это же намерение. Для меня звучит как МЫ НЕ СОБИРАЛИСЬ ПРИЙТИ ВОВРЕМЯ. Разве нет?

Татьяна, to be going to употребляется еще и для обозначения неизбежности действия. Видимо, это тот самый случай.

Я это понимаю, когда It's going to rain. А с одушевлённым подлежащим у меня to be going to ассоциируется только с намерением.(