Except speak English.
"Except for speaking English"
"With the exception of speaking English"
Would of been the proper sentences to use when attempting to convey that Alex speaks English in a less than proficient manner.
I would also like to inform you that Alex is bilingual, possibly multi-lingual, so we can automatically assume that he speaks at least twice as many languages as you.
Unless you include the language known as "dumbfuck"... you speak that well.