In the quiz sentence 'Cuando estés tan agobiado que no puedas relajarte, llámame.', can you explain the structure of this sentence.

Question

'Cuando' triggers the subjunctive 'estés', is there a double trigger due to 'Cuando estés tan agobiado que' causing 'no puedas relajarte' where 'puedas' is in the subjunctive or is 'no puedas relajarte' just in the imperative?

Answer

Hola Michael
The second part "no puedas relajarte" is also in the subjunctive because it is triggered by "que" (cuando estés tan agobiado que...). This part: "que no puedas relajarte" implies "that you may not be able to relax", therefore there is uncertainty. 
Does it clarify it for you? It is a complex structure.
Let us know if you have more doubts.
Gracias
Inma

Answer

Perfect explanation, thank you.  I understand the subjunctive in this case, but I hadn't seen this form of double trigger, with the subjunctive repeating in the same sentence.  The imperative didn't make sense to me.