Conditional with como
 

I came across a sentence structure that was in conditional that used como to mean if instead if si, but it didn't seem to follow the rules of si condicional.

"Como lo vuelvas a hacer te arrestarán."

I would think that if we used si in place of como, the sentence would have to read:

"Si lo vuelves a hacer te arrestarán."

I have also seen the sentence, "Como tengas experiencia te dan el trabajo."


I have never seen the present subjunctive follow si in a conditional frase,

(Condicional real presente)
Si tengo dinero, voy/iré de excursión.
(Condicional real pasado)
Si ha llegado, dímelo.
Si ha llegado, lo habrán visto.
Si ha llegado, lo han visto.
(Condicional irreal presente)
Si tuviera dinero, iría de excursión.
(Condicional irreal pasado)
Si hubiera tenido dinero, habría ido de excursión.
Si hubiera tenido dinero, hubiera ido de excursión.
Si hubiera tenido dinero, no estaría ahora aquí.

Are the above uses of como + present subjunctive unique to como and prohibited with si? Are they even real sentences? (I found one in a dictionary and one in a grammar book.) I'm confused.

Thanks in advance for your help!

como lo vuelvas a hacer :ne:si lo vuelves a hacer

si lo vuelves a hacer ---> in an imaginary world (space of events) where you 100% do this
como lo vuelvas a hacer ---> in the event you'd be doing this

si lo vuelves a hacer te arrestarán ---> mechanical description of consequence: Lo vuelves a hacer, te arrestan. No lo vuelves a hacer, no te arrestan. Si lo vuelves a hacer, te arrestan.

como lo vuelvas a hacer te arrestarán ---> a warning: in the event you do this you'll trigger a chain of events which will lead you to this

You may think of "si" as powerful enough to create a branch of reality where things happen without really being happening (indicative because they happen) with all the branch being kind of an isolated reality -hence the mechanical aspect-. "Como" has not such a strength so it introduces what is more a comment within the previous reality and not an independent hypothetical reality. The eventual aspect of that, the warning aspect and its discouraging intention (don't do it) are all three carried by subjunctive.

You know, Spanish verbal system: powerful, flexible ... difficult

"Como lo vuelvas a hacer te arrestarán."

"Si lo vuelves a hacer te arrestarán."

Well, yes. For me, the sentences above mean basically the same. They both refer to a hypothesis. We could say that the first one sounds a bit more threatening, whereas the second one sounds more "neutral", but they refer to a condition , in the same way as "If you do that again" and "in case you do that again" do in English.

This hypothesis is expressed by the verb "vuelvas" in the first one, and by the word "si" in the second one.

Let's compare:

Como lo vuelvas a hacer...--> You didn't do that yet, but IF you do it again...
Como lo vuelves a hacer...--> Since you are doing it again...
Como lo volviste a hacer...--> Since you did that again!...

I'm pointing this out to show how the word "como" itself doesn't have any "warning" implicit. What turns the sentence into a warning is the combination "como + subjuntive ---> subject + WILL + verb"

So, for events that may happen or not in the future, we use:

Si + indicative
Como + subjunctive
En caso de que + subjunctive


Are the above uses of como + present subjunctive unique to como and prohibited with si?

"Como" can be followed by any tense and any mood. "Si" clauses have their own "rules" for the use of the subjunctive, with expresses a high or a low degree of probability. Si can be followed by

Si lo haces ...:good:
Si lo hiciste ...:good:
Si lo hacías ...:good:
Si lo hicieras ...:good:
Si lo hubieras hecho ...:good:

Si cannot be followed by:

Si lo hagas :bad:
Si lo harás :bad:
Si lo habrás hecho :bad:
Si lo harías :bad:


Are they even real sentences?


What do you mean with this? Hehe! If you are asking if the sentences you wrote are correct yes, they are, perfectly correct and very common.