Which should you use, then or and then? Then is not a conjunction and cannot take the place of and.
| Incorrect: |
He glanced at them, then walked ahead. |
| Correct: |
He glanced at them and then walked ahead. |
Then usually functions as an adverb. When using then as an adverb, insert a semicolon or a period before then.
| Correct: |
He glanced at them; then he walked ahead. |
| Correct: |
He glanced at them. Then he walked ahead. |
