"To recognise the signs" means to identify or notice indications or clues that indicate a certain situation, condition, or event is happening or is likely to happen. Full definition
It helps to learn to recognise the signs of when you are under stress. (slaw.ca)
Equally, many parents are not aware of the potential for bullying in schools and won't recognise the signs in their own children. (educationbusinessuk.net)
Can't you guys recognise the signs are there. (justarsenal.com)