Frege says,We can regard a sentence as a mapping of a thought: corresponding to the whole–part relation of a thought and its parts we have, by and large, the same relation for the sentence and its parts. Things are different in the do- main of reference. We cannot say that Sweden is a part of the capital of Sweden.The reference of the parts of a sentence are not parts of the reference of the sentence. However: The sense of a part of the sentence is part of the sense of the sentence.