How to assign subtask to specific sprint

[Kan Wong]

Hello,

There is a need here to leave a task without sprint but assigning one of the subtask to specific sprint. The problem we having is how to add sprint field to subtask. And second, it is a proper way to use Jira that way. Thanks a lot.

[Jack]

Not really, no. Sprints should consist of story/task level issues. Subtasks are just a way to add some clarity or break the story into smaller bits of work. Regardless of whether you use subtasks or not the full story or task should be completed within the sprint. Now for subtasks and their usage in sprints, they inherit the sprint from their parent. 

[Nic Brough _Adaptavist_]

You put a sub-task in a sprint by placing its parent issue in the sprint.  Sub-tasks are a part of an issue, not separate stories in their own right, and hence can only be part of a sprint by virtue of their parent being in it.