Debe vs debería

Question

Can someone explain specifically how the tense of deber changes the meaning of these sentences?

¿Por qué cree que debería orar? (translated as Why do you think you should pray?)

and

¿Por qué cree que debe orar? (What do you think you should pray for?).

I feel like the first sentence could've been made clearer using "para qué" instead but I'm just wondering how you would explain the different meanings of those two sentences.

My thoughts are that the conditional deber implies a more abstract meaning to por qué, and thus "why", as opposed to just present tense debe means like if you were to pray right now what should you ask for. Does that make sense?

Answer 1

First, let's deal with your basic question, the difference between "debe" and "debería". I want to start with a simpler pair of sentences than yours.

Él cree que debe orar.
Él cree que debería orar.

Both of these can be translated by

He believes he should pray.

So what's the distinction in Spanish? The first sentence carries the implication that he is praying. The second one implies that he is not praying even though he believes he should be. This is a distinction that English does not make by simply altering the verb form. If an English speaker really wanted to make this clear, they would do so in the context of the rest of the conversation.

The Spanish speaker isn't necessarily thinking any more clearly than the English speaker. It's just that the language forces the Spanish speaker to make a choice.

If we then ask the question "why?" There are two more complexities added in.

The first is that the why might be about the reasons for prayer. For example, because God commands it, or because it will provide comfort. But we might want to know about the reasons for his belief.

The second is the distinction between "¿por qué?" and "¿para qué?". In English we have "what for?" but many speakers use "why?" with this meaning. That's not wrong, but it leaves some ambiguity.

Answer 2

I hope this helps:

The phrase ¿por qué cree que debería orar? has more emphasis in a hypothetic way to say it (imagine you are doing something). It's similar when one try to say for example: why would you do that?

The phrase ¿por qué cree que debe orar? is simply referring why you should do that action in present tense, as you mentioned earlier.

Just a side note. I think in this context, "deber" is more like an "ought to" rather than a "should". It has a stronger meaning.