Ne mets pas de sucre dans mon café.
Don't put sugar in my coffee.
Ne confonds pas le sucre et le sel.
Don't confuse sugar with salt.
Elle a confondu le sucre avec le sel.
She mistook the sugar for salt.
FrenchTextbook teaches rules like this, in a full beginner course.
162 lessons, 4,000+ exercises, and 6+ hours of audio.