Firstly, secondly, thirdly, first, second, third, first of all, lastly, to start with, in the first / second place, for one thing, for another thing
These expressions are used to show the structure of what we are saying.
Firstly, we need something to eat. Secondly, we need to find a place to live in. And thirdly, we need to find work.
Instead of firstly, secondly and thirdly we can use first, second and third. Note that the expressions firstly, secondly etc., are more formal and are more common in British than American English.
First, we need something to eat. Second, we need to find a place to live in. And third, we need to find work.
There are three reasons why I don’t want to hire him. To start with, he doesn’t have the required qualifications. For another thing, he lacks work experience. And thirdly, he is over forty.
There are three reasons why I don’t want to buy a tablet computer. For one thing, tablets don’t have physical keyboards. For another thing, they are expensive. And thirdly…
In the first place; in the second place
You should never have appointed him in the first place.
We only had four of these glasses in the first place, and now you’ve broken three of them.
In the first place, I don’t have enough money to buy a car. In the second place, I don’t need one.
Finally can introduce the last element in a series.
We must eradicate poverty. We must reduce unemployment. We must eliminate illiteracy. And finally we must increase productivity.