Transitional adverbs are words or phrases that writers use to move from one sentence to the next. They show the relationships between your sentences and paragraphs.
The transitional adverbs are more common in writing than in speech.
Here is a list of the most common transitional adverbs.
Phrases used to indicate the order of ideas or facts
Examples are: first, second, third, next, then, lastly etc.
Firstly, we need to find something to eat. Secondly, we need to find a place to live in. And thirdly, we need to find work.
Note that the expressions firstly, secondly, thirdly etc., are more formal that first, second, third etc. They are more common in British English than in American English.
Phrases used to explain, define or elaborate on an idea
Examples are: that is, in other words
Learning a language requires a great deal of time and patience. In other words, don’t expect quick results.
Phrases used to add information to what has already been said
Examples are: moreover, furthermore, in addition, as well as, what is more, besides
She is unwilling to work hard or learn new skills. What is more, she has trouble working as part of a team.
The flood victims are in desperate need of food and shelter. In addition, they urgently require doctors.
Note that transitional adverbs modify the entire sentence and hence they come at the beginning of a sentence.
Besides transitional adverbs, conjunctions and prepositions can be used to indicate the rhetorical structure of your text. Note that transitional adverbs do not connect sentences grammatically. They merely show the relation between your sentences. Conjunctions, on the other hand, join clauses into grammatically connected sentences.