The Classification of Words

WORD-ORDER IN SIMPLE SENTENCES 1. The Position of the Subject and the Predicate in the Sentence
§ 477. We have already dwelt upon the fact that in Modern "English syntactical relations of words in the sentence are very often indicated by the position the words occupy in the sen­tence.
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As known, Modern English is characterized by a rigid word-order in accordance with which the subject of declara­tive sentences, as a rule, precedes the predicate. This is the so-called direct order of words.
E. g. The assistant greeted the professor.
Any deviation from the rigid order of words is termed inversion. It must be said that an unusual position of any part of the sentence may be treated as inversion in the broad sense of the word.
E. g. This I know ... where the object precedes the subject. But, for the most part, the term 'inversion' is used in its narrow meaning with regard to the principal parts of the sen­tence. It indicates that the predicate precedes the subject (indirect order of words). Often has he recollected the glorious days of the Civil War. Here we use the term 'inversion' in the narrow sense of the word.
In an overwhelming majority of cases only the structural (part of the) predicate is placed before the subject. Is he writing? May I enter? Where does he live?
Cases like Away ran the horse are comparatively rare.
§ 478. This is how W. Twaddell sums up the principal cases of inversion in English, which he calls 'the sequence Auxili­ary -+ subject': "The most common occasion for the sequence Auxiliary + subject is with interrogation. Other, semi-mar­ginal constructions with this sequence are

1. 
   In formal styles, conditional inversion, usually with
   had + subject + participle.
   
2. 
   In formal styles, after sentence-initial elements with
   negative or res'trictive meanings like "Never, Nor, Neither,
   Nowhere else, Scarcely, Seldom, Not only".
   
3. 
   Informally after "So" in the meaning "also, likewise,
   too". ^l
   

E. g. Did you enjoy it?
Had she foreseen it, she would have acted differently. Nowhere else will you see that. He studies English. So do I.
¹ W. F. Twaddell. The English Verb Auxiliaries. 1960.
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