How to make it so that users can create subtasks but cannot create task?

[alex gabriel]

The administrator creates tasks and subtasks. It is necessary to make so that users could see both tasks and subtasks, and create only subtasks. It must prevent users from creating tasks and permit to create subtask. 

[Nic Brough -Adaptavist-]

You will need coding to do this, as "create issue" permission really is for create in a project.  It's not limited by issue type.

There are some tricks you can play with javascript, and maybe fields that block things, but these are ugly for your users and usually easy to bypass.

[alex gabriel]

Could there be any other options? For example, warn the administrator about the intention to create tasks? The main task is to monitor the activities of users.

[Nic Brough -Adaptavist-]

How would a system know that a user intends to create a task until the user actually does?

Monitoring others is easy in JIRA though, you can set up notifications to send emails when issues are created, and simply ask "who created issues" and it'll tell you when it was done and give you any or all of the rest of the data on the issue.

[alex gabriel]

Thank you very much for the answer!

[alex gabriel]

And can I do so that the user can not edit the tasks and can only edit the subtasks?

[Nic Brough -Adaptavist-]

See the original answer.