Enumeration & Coherence
Speaking
| First/Firstly | Second/Secondly | Third/Thirdly | 
| first of all | in addition to | |
| at first | on top of sth (unpleasant) | |
Writing
Speaking
| First/Firstly | Second/Secondly | Third/Thirdly | 
| first of all | in addition to | |
| at first | on top of sth (unpleasant) | |
Writing