General: They speak English fluently.
Special: They speak English at their language classes.
Tail: They speak English at lessons, as it is a requirement for their course.
Alternative: At lessons, they converse in English.
General: They speak English fluently.
Special: They speak English at their language classes.
Tail: They speak English at lessons, as it is a requirement for their course.
Alternative: At lessons, they converse in English.