Si es que

Question

Hola,How does the meaning change when es que is preceded by si?    For example:Si es que no podía ni hablar.

Accepted Answer

Hola Jamie,
it is quite difficult to translate into English as there is no clear equivalent, but when we use "si es que..." it would be a combination of consolidating what it was said before and at the same time it could explain the cause of what was just said (which is what "es que ..." is normally used for). To give it some context, imagine this little dialogue:

A: Esta semana no he conseguido terminar todo el trabajo que tenía atrasado. Quizás sea porque me he acostado bastante tarde algunos días porque he salido de copas...
B: Si es que eres un desastre; deberías formalizarte un poco.
 
A: I haven't managed to finish all the backlog I had this week. Maybe because I went to bed quite late some days as I went out drinking... 
B: The thing is/ Well, no surprise there / you are a mess; you should settle down a bit.

It would be like saying "Well, that is because you are a mess, since you have very bad habits."
I hope this makes sense. 
Saludos
Inma

Answer

Can Si es que… and Es que… be used interchangeably then? I’m not quite sure I understand what you mean by “consolidating what was said before.”

Answer

When I said "consolidating what was said before" I meant to "confirm" somehow whatever was talked about and adding a possible cause.  For example, if I say:

Ya no me queda dinero en el banco, y recibí mi paga hace 3 días.
I have no money left in the bank and I only received my pay 3 days ago.

Then my friend could say:

Si es que no tienes remedio, eres muy irresponsable y gastas demasiado.
Well, that is because you are a lost cause, you are very irresponsible and you spend too much.

So, with this "Si es que..." she is somehow confirming the fact that I am a bit of a mess and that being the cause of my problems.
You could have used "Es que..." without "si" here, with the same meaning, but using "si" puts a bit more emphasis. 
Saludos