I wonder which of the following sentences is grammatically right?
- So happy he looks.
- So happy does he look.
Neither example is a complete sentence.
Example 1 does not seem natural to my (American) ear.
Example 2 seems poetic and old-fashioned. I expect the second example to be followed by a cause or a corollary. For example:
- So happy does he look,
now that sadness
he hath forsook.
By the way, "hath" and "forsook" are very rare in modern English. Also, "hath forsaken" is probably better grammatically than "hath forsook". Unfortunately, "forsaken" does not rhyme with "look".