My main research interest is linguistic polarity and how polarity phenomena could be used to account for the fact that certain adverbs do not seem to cooccur. Postive polarity is likely to be particularly relevant here, which is intersting, since positive polarity is clearly not at all as well researched as negative polarity.

Right now, I am conducting empirical research on prepositional passives in English. This is another area where more knowledge is needed. 

In my dissertation (Beijer 2005) I put to the test Cinques's (1999) proposal concerning the relative order of adverbs in the I-domain. I do this both theoretically and empirically.

Cinque's idea is that adverbs of different types have a certain relative order, due to them occupying the specifier positions of different hierarchically ordered functional projections. Beijer (2005) investigates if the proposed order appears to be correct for English and Swedish.

Through this investigation it became apparent that certain adverbs do not cooccur. This may have different reasons, but one possibility is that some non-occurring adverb combinations are absent due to the adverbs having different polarity, so that one of them makes the other one impossible, or the context in question is such that it can only host one of them. This is indeed the case for negative polarity and NPIs, but may also be the case for positive polarity and PPIs