"I speak only English" vs "I only speak English"

In the first sentence, only modifies English, and there is always the implication with the first version that you can speak another language, you just won't. In the second sentence, only modifies speak, implying that it is the only language that you are capable of speaking.

https://forum.wordreference.com/threads/difference-between-i-speak-only-and-i-only-speak.1575024/