I don't have any____in learning English grammar.but I often make speling mistakesdifficultytroublesdifficultiesproblems

I don't have any____in learning English grammar.but I often make speling mistakesdifficultytroublesdifficultiesproblems
I don't have any____in learning English grammar.but I often make speling mistakes
difficulty
troubles
difficulties
problems

I don't have any____in learning English grammar.but I often make speling mistakesdifficultytroublesdifficultiesproblems
difficulty
其他三个都是复数,可以一起排除.