A knowledge structure required in order to understand a particular word or related set of words.

The semantic frame is central to the theory of frame semantics. To illustrate, consider the related group of words buy, sell, pay, spend, cost, charge, tender, change, and so on. According to frame semantics, in order to understand these words, we need access to a commercial event frame, which provides the background knowledge, based on experience, to which these words relate. For instance, the commercial event frame includes a number of attributes which must include, at the very least, buyer, seller, goods and money.

Thus a given word foregrounds a particular part of the semantic frame to which it is relativized, and yet cannot be understood without the other elements which make up the frame. One consequence of this is that a word provides a 'route' through a particular frame. That is, as words relate to 'slots' in the frame, they directly relate certain elements within a frame.

This manifests itself in linguistic terms as valence or argument structure.

Valence concerns the ways in which lexical items like verbs can be combined with other words to make grammatical sentences. For example, while buy and pay relate to the actions of the buyer, buy relates to the interaction between the buyer and the goods, while pay relates to the interaction between the buyer and the seller. This knowledge, which is a consequence of the commercial event frame, has consequences for grammatical organization:

1. (a) John bought the car (from the salesperson) (b) *John bought the salesperson
2. (a) John paid the salesperson (for the car) (b) *John paid the car The valence of verbs in these utterances (how they combine and with what) is a consequence of how they are related in the commercial event semantic frame.