This section is from the book "Lessons In English", by Chestine Gowdy, Lora M. Dexheimer. Also available from Amazon: Lessons in English.
An Independent Expression is an expression that has some connection in thought but no grammatical connection with the rest of the sentence.
A Nominative of Address (§ 153) is used independently.
An Interjection is a word used independently to ex-press sudden feeling but not used as a name.
Examples : Oh, O, alas, ah, heigh-ho.
An Absolute Phrase is an independent expression con-sisting of a noun or a pronoun and its adjunct. The first word of the adjunct is generally a verbal; thus:
Mary being tired, we went home early; Robin Hood turned away, the sheriff following him; The planting is generally done in beds, the seeds being sown broadcast.
 
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