Interjections are usually defined as an anomalous grammatical class in
most levels of analysis. This paper presents an alternative account of
interjections within the frameworks of prototype theory, on the one hand,
and grammaticalization, on the other hand. Adopting a prototype approach
to grammatical categorization, interjections are better seen as peripheral
instances of sentences, since they behave as maximal units of syntax but
do not exhibit a subject plus predicate structure. On the other hand.
grammaticalization theory accounts for the distinction between primary
and secondary interjections and allows to establish the limits between
interjections and phrases
