My English is not so good.
My English is poor.
I am not 100% fluent.
My English is poor≠ 我英语不好
poor贫穷的;不幸的;糟糕的;劣质的
My English is terrible/bad我的英语很糟糕
I am not good at English我的英语不太好
例句:
My English is bad, I do not understand what you said.我的英语很糟糕,我没听懂你说了什么。
My English is a little rustyI don t speak much English我不太会说英语
My English is a little rusty我的英语有点生疏了,我的英语不太熟练
My English is okay我的英语水平一般般My English is not that good我的英语没那么好