Si

Si
 

It seems that i have almost won my battle against the subjunctive monster, i just have a quick question about using "si"

i know that we can use si in two ways:

to express that the speaker is fairly optimistic of something, or better still he doesnt have any real doubts:

si tengo dinero..compraré....

and also to express a hypothetical or fairly unlikely situation:

si tuviera dinero...compraría....

now my question is, specifically using si at the beginning of a sentence relating to a future time:

si vienen mañana.....this is suggesting that maybe they will or maybe they will not come?

whereas:

si vinieran mañana....this is suggsting that the speaker feels it is fairly unlikely or he doesnt expect them to arrive tommorow?

subtle differences i know, but..i need to know!

Si vienen [si + presente simple]... tendré preparada la cena [futuro simple]
Si vinieran [si + imperfecto subjuntivo] tendría preparada la cena [condicional simple]

La estructura "si vengan" [si + presente subjuntivo] es muy rara e infrecuente. Sólo se da con relativa frecuencia en algunas zonas de Latinoamérica, entre ellas, partes de México. Normalmente va acompañada de un verbo que marque duda o incertidumbre:

-He perdido la cartera. No sé si tenga dinero para comprar el almuerzo.

¿Se entiende bien?

si tengo dinero ... is also hypothetical. The basic structure is "si tuviera .... compraría". Changing subjuntive to indicative makes it more probable: "si tengo dinero ... lo compro / lo compraré" makes it "a plan", not meaning it's more probable for me to have the money but very unlikely for me to change my mind in the future about what to do in case I get ahold of that money.

You have to take note of all the basic structures that allow a change of mode with specific meaning, including using subjunctive with known information and indicative with new information. For instance:

quizás venga (basic form; expresses doubt)
quizás viene (constructed by contrast; there's less doubt, or there's a certain expectation or interest in a positive outcome -as if it is "a lo mejor"-)

si se sirve/desea/quiere acompañarme (basic form; courtesy)
si se sirviera/deseara/quisiera acompañarme (contructed by contrast; extreme courtesy)

Indicative focuses things, subjunctive blurs them:

alguien que habla español (some specific person, someone)
alguien que hable español (a generic person with such ability, anyone)

que bueno que terminan las clases (new information; a comment that is a little bit of an announcement)
que bueno que terminen las clases (known information; comment about old information)

Thanks guys, i think that i have got it.