First of all,the sizes. They have one obvious feature,a raven is bigger than a crow in size.Then,the tails.A raven’s tail is in a rhomboic shape while a crow’s is a fan-shaped one.
Secondly,the sentence patterns.All kinds of sentence patterns are in it.I give an example.“I only wish that you had helped me just now,even if it had been only with those words,for