Is the usage of "I thank you" correct? [closed]
While we normally just say or write, "Thank you" (in which "I" is assumed), it is perfectly acceptable to say or write, "I thank you" instead. It adds a subtle emphasis and personalization to your response, although you are correct that it is relatively uncommon compared to the usual form. However, it is not considered rare or awkward usage.
"Thank you" is the popular usage.
You are correct in that "I thank you" is a bit awkward and rarely used.
In any case, "I thank you" is grammatically okay.