French language Q&A Forum

The two sentences below look almost exactly the same, in both 'they' know a fact (what time the shop closes).

Presumably, then, its just that in the 2nd sentence the verb is followed by a noun and that alone determins that 'conaitre' should be used, (and it's nothing to do with 'they' knowing a fact)?

Ils savent à quelle heure le magasin ferme. They know what time the shop closes.

Ils connaissent l'horaire de fermeture du magasin.
They know the shop closing time.

I never get this right. Please, is there a summary of when we would not write the "s" at the end of the tu form verb in l'imperatif ?

Thank you!