Is past subjunctive necessary when using "il fallait que"

Question

When translating "they had to find a way to do it" in a formal written text, I'm not sure whether or not to use the past subjunctive if the idea of past is already encoded in il fallait que.

The way I feel I would say this, at least in speech, is il fallait qu'elles trouvent une façon de le faire but I'm unsure if I should be using a past form of the subjunctive instead, such as aient trouvé.

My reasoning behind going for the first option rather than the second is that because the idea of past is already encoded once in fallait, including it in the subjunctive form again would suggest that from the point of reference (past), they already should have done it.

I hope I'm explaining this clearly enough; any help and explanations of why you should use one form over the other would be greatly appreciated!

Answer 1

To be strictly in accordance with the grammatical rules, you should indeed also apply the concordance des temps with the subjunctive, therefore using either the subjonctif imparfait or the subjonctif plus-que-parfait for the simultaneity or the anteriority of the subordinate action, respectively.

This would thus be :

il fallait qu'elles trouvassent ...

il fallait que tu vinsses ...

In practice, as far as I can tell, most people use the subjonctif présent or the subjonctif passé instead, especially if you are speaking. So that you should not use the past forms when you speak if you don't want to sound old fashioned. I find it a little sad, but that's the way it is.

As a last remark,

il fallait qu'elles aient trouvé...

would be interpreted as an action that took place before "il fallait" because the subjonctif passé replaces the subjonctif plus-que-parfait in this (wrong but admitted in practice) context.