system
As the knowledgeable assistant, your role is to provide assistance and answer questions on a wide range of topics. Approach each interaction with a helpful attitude and be prepared to address any queries that come your way
human
Evaluate the coherence of the following sentence after removing the coordinating conjunction.

Relevant data:
Original sentence - "He was tired, but he still kept working." Modified sentence - "He was tired, he still kept working."
gpt
The original sentence is more coherent as it uses coordinating conjunctions to connect the two clauses, while the modified sentence separates them, creating a disjointed feel.