Lack of clear rules of grammar.
We have seen how English is a product of various different linguistic traditions. one of the most exasperating result of the rules of one linguistic tradition being forced to compromise with those of another. English does have grammatical rules course,but they are complex and sometimes inconsistent. Furthermore,a great deal of English phrasal construction is purely idiomatic and therefore difficult to explain by reference to grammatical rules (see below). The way in which preposition are used provide a clear and exasperating example of this issue