make sub task start before their master task starts

[anetteqqq]

Hi. How can i set a sub task to start before the master task starts? I have a predecessor that ends before the master task starts, and I want this to trigger the sub task to start. But how can I do that, without setting a constraint to force start on a specific date? I really just want the predecessor to decide and "ignore" that the master task starts later. Also, want it to be auto-scheduled, not manual.



Is this at all possible?

See attachment, trying to explain that it is task 2.1 that is the trouble. Thanks.