Usually at the beginning (or middle or end) of a sentence, usually separated by a comma.
It can also be represented by prepositional phrases, nonfinite clauses, nonverb clauses, and finite clauses.
Linking Adverbial
It is usually represented by conjunctive adverbs, interpretive adverbs and related prepositional phrases, which can play a role in linking phrases, clauses and sentences.
Calling upon the language
Parenthesis
A positive at the beginning of a sentence
The negative word at the beginning of the sentence
