Clever for Obliging. In this sense the word was once in general use in the United States, but is now seldom heard and life here is less insupportable.
Climb down. In climbing one ascends.
Coat for Coating. "A coat of paint, or varnish." If we coat something we produce a coating, not a coat.
Collateral Descendant. There can be none: a "collateral descendant" is not a descendant.
Colonel, Judge, Governor, etc., for Mister. Give a man a title only if it belongs to him, and only while it belongs to him.
Combine for Combination. The word, in this sense, has something of the meaning of conspiracy, but there is no justification for it as a noun, in any sense.
Commence for Begin. This is not actually incorrect, but—well, it is a matter of taste.
Commencement for Termination. A contribution to our noble tongue by its scholastic conservators, "commencement day" being their name for the last day of the collegiate year. It is ingeniously defended on the ground that on that day those on whom degrees are bestowed commence to hold them. Lovely!
Commit Suicide. Instead of "He committed suicide," say, He killed himself, or, He took his life. For married we do not say "committed matrimony." Unfortunately most of us do say, "got married," which is almost as bad. For lack of a suitable verb we just sometimes say committed this or that, as in the instance of bigamy, for the verb to bigam is a blessing that is still in store for us.
Compare with for Compare to. "He had the immodesty to compare himself with Shakespeare." Nothing necessarily immodest in that. Comparison with may be for observing a difference; comparison to affirms a similarity.