What are the possible structures that follow the phrase: let somebody know. For example, is "Let me know your opinion" correct?
The McGraw-Hill Dictionary of American Idioms and Phrasal Verbs has the entry:
There are various common structures:
Please let me know about it. / Please let me know.
Let me know what you think. // Let me know what/how you feel about it. // Let me know if you are coming.
Let me know your name/favourite song // answer // thoughts/opinion/heart/preference/take on this matter/... This apparently ditransitive construction is really a shortening of the related wh-clause 'Let me know what your name is' etc.