In this paper, the acquisition of Swedish syntax of negation by adult second-language learners has been studied. Insights into the route of acquisition have been gained through a close examination of the learners' variation in their placement of the negative element, i.e., the way in which some learners variably place the negation before and after the finite verb. This type of variation has previously been seen as random and irregular, but through application of devices for the study of variable data, such as implicational scales (DeCamp 1971), variable rules (Labov 1969) and linguistic continua (DeCamp 1971, Bickerton 1975), it has been possible to discover regular patterns in the variation. Such regularities have previously been found in sound system acquisition by second-language learners (L. Dickerson 1975, W. Dickerson 1976).

The route of acquisition has been found to be highly regular for the group of 160 subjects who were examined in this study, and furthermore, independent of differences in background factors of the learners, such as length of education and knowledge of foreign languages. Most interestingly, the route of acquisition has also been found to be the same for learners with different source languages.

Thus the findings reported in this paper suggest that the process of acquisition of grammatical structures is a regular and dynamic one, in that there is a successive and continuous transition from one state to another. The behavior of a group of backsliders in the same syntactic area has also been studied. It is found that what is acquired last is also the first to be given up. These findings are in agreement with the Jakobsonian view of a natural sequence in language acquisition and language loss.