He's a real genius but he has difficulty verbalizing his ideas.
他确实是个天才，可是难以用语言表达他的思想。
牛津词典
...his inability to verbalize his feelings.
他无法用言语表达自己的感情
I find it difficult to verbalize.
我感到很难用言语表达.
期刊摘选
I cannot verbalize it in a concrete way. I am sometimes quite confused.
就是很多事情我是说不出一个具体的东西,有时候也挺迷惑的.
期刊摘选
This depressed patient does not verbalize.
这位情绪低落的病人不爱说话.
期刊摘选
Watch out for how they verbalize with others.
2020年考研真题（英语二）阅读理解 Section Ⅱ"This lawyer verbalizes and is rather tedious"
"She talks a lot of nonsense"
"This depressed patient does not verbalize"
"She expressed her anger"
"He uttered a curse"
"many English nouns have become verbalized"