我相信我能把英语学好用英语怎么说

"I believe I can learn English well" 的英文表达是 "I believe in my ability to master English."

"I believe" 是 "相信" 的意思，"in my ability" 是 "我的能力" 的意思，"to master" 是 "掌握" 的意思，"English" 是 "英语" 的意思。

例句：

"I believe I can pass the TOEFL exam if I study hard." (我相信只要我努力学习就能通过托福考试)
"I believe in my ability to become fluent in Spanish." (我相信我能熟练地说西班牙语)
"I believe I can succeed in this job with my skills and hard work." (我相信我能凭借自己的技能和努力工作成功)