according to this article (Use 15), it's against the rule to use an article 'the' before a plural countable noun (e.g. pictures, flowers, horses etc.)
sentence: I've just sent you the pictures
In case if I can use it sometimes, please describe me the cases when I can use article 'the' with plural countable noun
Thank you in advance
When you want to make a general statement about something, and the noun is countable, you don't use the article:
Horses have hooves.
The above means "All horses".
If you use the article, you're not referring to all horses, but to specific horses:
The horses have been training in a simulated high altitude environment with low oxygen, to improve their lung capacity for the big race.
If you say:
The horses have hooves.
someone might reply, "Of course they do! All horses have hooves".
