Subjunctive when talking about something in the past
The tutorials I have on the past subjunctive say that it is only used when the verb in the main clause (before que) is in the preterite, imperfect, past perfect, or conditional. But what about when we talk in the present about a past action? For example, "It is likely that someone took it" - the main clause is in the present, but if we use the present subjunctive here is would (I think) mean "It's probable that someone takes it". What is the correct usage here?
Es probable que alguíen lo tomará
Whenever you are speaking of something that could have happened, but may not have, especially when you have the verb+que+verb structure, you will use subjunctive. Wishes, emotions, doubts, desires, abstract questions, negative questions, and god clauses all bring about the subjunctive. If you would like, I would be more than happy to sit down with you on skype sometime to help explain if this makes no sense.