Doesn't anybody know where my coat is? ( change to assertive )
To convert interrogative sentences to assertive sentences, an important point to remember is - 'if the question is in the negative, the (assertive) sentence must be positive/ affirmative. whereas, if the question is positive, the corresponding assertive sentence must be in the negative.
Hence, the correct answer is - Nobody knows where my coat is.
Hence, the correct answer is - Nobody knows where my coat is.