"desearía" vs "deseo" plus present subjunctive vs imperfect subjunctive?

Question

The word desear means to want, to wish. I've seen two usages:

1. Deseo que estés aquí. (I wish you are here.)
2. Yo desearía que estuvieras aquí. (I wish you were here.)

Questions:

1. What's the difference between present and conditional (for desear)?

2. Can I say these?

   Deseo que estuvieras aquí.
   Yo desearía que estés aquí.

Answer 1

Desear in Spanish means "to wish" indeed, but when used in present (deseo) it sounds more like a request than a wish: I'd only use deseo when talking to a wishing dwell :D i.e. when I actually expect the listener to satisfy my wish. You know the saying "your wish is my command"? Well, deseo is used for that kind of "wishes".

Desearía que estuvieras aquí.

That's just me telling you I miss you. You being here is not possible, but I wish it were.

Deseo que estés aquí.

That's me strongly asking you to be here. You being here is "doable", and I'm telling you that I want you to do it.

Desearía que estés aquí.

That's just the courtesy form for the previous one. I'm still asking you to be here, but I don't want to come off as bossy.

Deseo que estuvieras aquí.

This one seems to me idiomatically (if not grammatically) incorrect. The gist of it is that the subjunctive is used for things that are (currently) not possible, so it clashes with the use of present deseo (used for very possible and expected things, as explained above).

Answer 2

First, let's see what the difference is between your first two sentences:

1. Deseo que estés aquí = I want you to be here.

2. Yo desearía que estuvieras aquí = I wish you were here.

The first sentence comes across as quite assertive. The second acknowledges that it's impossible for you to be here (for example, maybe you're out of town). But note that although this is technically correct, a more natural way of expressing this would be

Yo quisiera que estuvieras aquí.

which means the same thing but is more comfortable to pronounce.

Now for your questions. "Desearía" sounds weird, and "quisiera" is a special case, so let me explain it with a different verb, pedir:

(a) Te pido que hables con mi hermano mañana.

(b) Te pediría que hablaras con mi hermano mañana.

(a) is more direct, (b) is more gentle. It's just a difference of tone.

Now, how can the tenses be safely combined in one sentence? There are two patterns to choose from:

{present} ... {present subjunctive} e.g. Pido que hables.

{conditional} ... {past subjunctive} e.g. Pediría que hablaras.

If you want to have a slightly similar construction in English, as motivation for the combination conditional ... past subjunctive, you could think (very loosely) of this:

I would have liked you to have spoken.

Of course it's not the same but it could possibly help you build some intuitive feel for the pattern.

Answer 3

Present and past subjunctive mood carry different connotations in Spanish depending on the structure.

This is how I perceive it:

• Deseo que estés aquí. (= this is something I want to happen in the future: in a couple of hours, tomorrow, next week, etc.)
• Desearía que estuvieras aquí. (= this is something I want to happen now.)

You will often encounter another one paraphrased as deseo que estuvieras aquí; although, I can't ensure that this construction is totally correct.