A study of the way in which pragmatic factors can determine the interpretation of structurally ambiguous gapped sentences such as 'Bob gave Sally a savings bond and Susan a set of encyclopedias' (in the case of left gapping Bob gave Susan a set of encyclopedias; in the case of internal gapping Susan gave Sally a set of encyclopedias). The first principle is said to be that the hearer establishes a pragmatic parallel between the gapped conjunct and the ungapped one based on his assumptions about the speaker's knowledge of a given context, and that he thus decides which one of the readings is pragmatically plausible. It is shown that gapping interacts with the factivity hierarchy: emotive factives and to a lesser degree non-emotives and inchoatives do not permit acceptable internal gap readings because the presupposition carries over into the gapped conjunct.