Without getting into this discussion myself (my Spanish is limited to 'buenos dias'), I will tell you that your 'informal' sentences are too wrong to teach; you will hear some of them, but their use even in spoken English is nonstandard at best.

Hi, I think I'm more clear now, and I have to learn subjunctive just as it is, without the informal 'noise' for the 3º person, thanks a lot for this explanation. By the way I asked a question because in a book of Cambridge University Press, the author gives these examples:
They recommended that he should give up writing.
They recommended that he give up writing (more formal)
They recommended that he gives up writing (less formal).
I just thought that the third sentence could be a best way for learning, but now I know the subtle meanings. thanks.

First, let me make a few observations.

1. All wishes are counterfactual. It makes no sense to wish for what you already have. The Queen of England does not say, "I wish I were the Queen of England". If I am six feet tall, I do not say, "I wish I were six feet tall". So every wish is a wish for something to be different from what we know it to be.

2. "wish" is a little strange in the way it affects the interpretation of the tense forms in the proposition which follows it. Specifically, to express a wish about the present, the simple past* is used; to express a wish about the past, the past perfect* is used.

3. The present tense cannot express the perfective aspect of a verb, that is, it cannot express a finished punctual action. Therefore, in the tense-shifted world of the propositions which follow "wish", the past cannot express a punctual action. Here's an example: "I buy shoes" cannot have a punctual interpretation. Therefore, neither can "I wish I bought shoes". In both cases, a habitual aspect is signaled. To express the perfective aspect, it would be necessary to say "I bought a pair of shoes". Likewise, we must say "I wish I had bought a pair of shoes", not "I wish I bought a pair of shoes." Nevertheless, to complicate matters, people sometimes do say "I wish I bought a pair of shoes" when they mean "I wish I had bought a pair of shoes".

*Technically, these are the past subjunctive and the past perfect subjunctive. The past subjunctive is indistinguishable from the simple past except for the verb "to be", which is always "were" in the past subjunctive, regardless of person or number. The past perfect subjunctive is completely indistinguishable from the past perfect. Not even the verb "to be" is an exception. "had been" is the form in both past perfect tenses, whether subjunctive or not.

Now for some examples:

A wish for something in the past, i.e., a wish that the past had been different, a wish for the past to have been different. In these, a perfective (past punctual act) may occur in the proposition which expresses what is wished.

I wish you had told me.
I wish I had seen him while he was in town.
Don't you wish Larry had been there to see it? It was hilarious.
They wish I had been quicker to respond to their request.
Do you ever wish you had been born into a rich family?
We wish our son had been accepted into the university of his choice.
I wish I had bought that leather coat when it was on sale.

A wish for something in the present, i.e., a wish that the present were different, a wish for the present to be different. In these, only imperfective aspect (something stative or habitual) may occur in the proposition which expresses what is wished.

You're probably wishing that you lived somewhere else.
"I wish my husband loved me," said Sara, with a sigh.
Paul wishes he knew how to solve that problem.
I wish I had enough money to buy that car.
I wish I were rich. I wish I were famous.

A wish for something in the future, i.e., a wish that the future would be different, a wish for the future to be different.

Note there is something anomalous here. In the case of the past and the present, we already know what is true and real. Because we know what the truth and the reality of the situation was (or is) we can wish that it had been (or were) different. But no one knows the future. How is it possible then to wish that it will be different? Different from what? Different from another possible future which we know equally poorly?

Because of this anomaly, there is not much need for a standard way to wish for something in the future. The verb "wish" is usually changed to "want" or "hope" for such cases. Nevertheless, there is a construction with "wish" that does come close to wishing for a different future, or at least wishing for a particular future which may be less likely than what is desired. The construction I have in mind is "...wish (that) ... would ..." Again, note the tense-shifted world of "wish": The 'present' is "will"; the 'past (subjunctive)' of "will" is "would". So to express a wish for something in the future, we use the 'past of the future', namely "would".

In this construction, the person wishing and the person doing what is wished are almost always different. "I wish I would ...", "You wish you would ...", (and so on) are not extremely logical. For example, if I want to watch TV, I just turn on the TV and watch. I don't say "I wish I would watch TV", because I am quite capable of granting my own wish! The two persons can be the same, however, if what is wished is that something that can be seen as happening to the subject: "The movie star wishes she would get more fan mail" or "I wish I would win the lottery".

I wish the teacher would stop droning on.
I wish you would be more polite.
He wishes that you would come and visit him more often.
I'll bet you wish that your wife would serve you breakfast in bed.
My parents wish that I would get better grades.

Here are the (approximately) equivalent paraphrases with "want" and "hope".

I want the teach to stop droning on. I hope the teacher will stop droning on.
I want you to be more polite. I hope you'll be more polite.
He wants you to come and visit him more often. He hopes you will come and visit him more often.
I'll bet you want your wife to serve you breakfast in bed. I'll bet you're hoping your wife will serve you breakfast in bed.
My parents want me to get better grades. My parents hope that I'll get better grades.


CJ