When do I use an infinitive after Чтобы and when do I use the verb in the past?
This is confusing me when Чтобы is used to express the purpose of one action by another. I mean sentences like these:
I woke up early to catch the train.
I woke up early so that we catch the train.
I'm inclined to think that the absence of a subject in the subordinate clause after чтобы is why the infinitive is used. Maybe when the subject is clear from context?
Я проснулся рано чтобы успеть на поезд.
Я проснулся рано чтобы мы успели на поезд.
Are these sentences correct?
In other usages of Чтобы, things seem clearer to me:
Скажи ему чтобы не переживал.
У меня нет времени чтобы играть.
Are these correct? Did I miss anything of relevance?