As a learner of English as a second language, the most challenging thing for me is being/becoming as fluent as a native speaker. Actually I am doing my best. I practice it daily, including listening, which helps me a lot.

As a second-language learner of the English language, the most challenging thing for me is being fluent as a native speaker. I do my best to do so I practice it daily in addition to listening which helps me a lot.

As a second-language learner of English language, the most challenging thing for me is being fluent as a native speaker. Actually, I am trying to do my best to do so. I practice it daily in addition to listening, which helps me a lot.