information structure in English

Word order in English is rigid where information structure is concerned. The subject precedes the verb and the object follows it, and moving a constituent for emphasis is available only in a few marked constructions rather than as a general option. A language whose order is free can put the focused element wherever the focus position is and change nothing else. English cannot, so it does the same work by other means.

The primary means is prosody, and it is the one channel this record cannot show in writing. The nuclear accent falls on the constituent carrying the new content, and shifting it changes what the clause asserts while changing not one word of it. That is a grammatical device with a systematic effect, and it is the default: most focus marking in the spoken language is done this way and nothing else is added.

Beside it stands a set of constructions, each a multi-word frame rather than a marker. The cleft splits a clause in two and puts the focused element in the first half. The reversed cleft does the same with the halves in the other order. The existential frame introduces a referent without making it the subject of the predicate. The passive promotes a non-agent to subject and is used as often for information flow as for anything to do with voice, which is why it appears in this record as well as in the voice one. Preposing moves a constituent to the front and marks it as what the clause is about, and it is grammatical only under conditions the discourse supplies.

The state is periphrastic because every one of these realizers is a frame or a prosodic pattern and none is an affix or an inflected form. The obligatoriness is optional because no clause is required to mark any of it: an unmarked clause with a default accent is grammatical and merely says less.