If you were to go home, you would feel better
versus
If you went home, you would feel better
versus
If you will go home, you will feel better
Are all the above correct? Are there circumstances where one is preferable over the other? Or, are some of them just informal colloquialisms?
Is one form always more preferable than the other? In other words, were I to always use the "If I were to ..." form, would I always be correct?
The first form "If you were to go home, you would feel better." should be grammatically correct, but it sounds rather strange to me.
The second form "If you went home, you would feel better." is grammatically absolutely correct and also expresses the right thing. It is a so-called Conditional Clause of Type II which means that the event in question (i.e. you go home) is improbable but still possible. In general such a clause is constructed according to the pattern: If + simple past, would/could/might + infinitive.
The third form "If you will go home you will feel better" is incorrect. If you slightly adjust it to "If you go home, you will feel better." you get a so-called Conditional Clause of Type I which expresses that the event in question is likely to happen. In general a Type I If-clause follows the pattern: If + simple present, will-future or can/must/might+infinitive or imperative.
There is also a Type III, which, in your case, would be "If you had gone home, you would have felt better." It implies that the event in question is impossible, because you are talking about the past. In general, Type III follows the pattern: If + past perfect, would/could/might + have + past participle.
Other conditional if-clauses that do not fall into one of the above categories are usually grammatically incorrect. As always, there might be some exceptions and special cases, but the above is definitely a good guideline.
EDIT: People also sometimes speak of a Type 0 if-clause which addresses something that is generally true, for example: If it rains, I take out my umbrella. The construction is fairly simple, as you see.
It's not obvious from the second-person ("you") example, but if you view it in first person ("I"):
If I were to go home, I would feel better.
it becomes clear that this is an expression in the subjunctive mood. This is something that other languages (particularly French, in my experience) use relatively frequently, but English doesn't so much. Idiomatically, it is used to express a counterfactual dependent clause. In this case, for example, the sentence also implies that I am not actually in the process of going home at the time the sentence is written/spoken.
The most common usage of the subjunctive in English is probably the phrase lead,
If I were you, I would {something}
because I can never be you, this is always counterfactual.
Suggested further reading: http://en.wikipedia.org/wiki/English_subjunctive
Only the first example is truly correct. The second and last have tense-disagreement in the verbs. The second switches tense from a simple indicative past tense verb in the beginning (with, we will assume, an implied hypothetical). The sentence then switches to a subjunctive verb at the end. Subjunctive in both verbs is the correct conjugation for a hypothetical sentence like this.
The first example exhibits the correct agreement with the subjunctive (hypothetical), in both verbs. The subjective just isn't commonly used as much in English these days, as we are being rudely interrupted by would-be barbarians who would, were they to have their way, convert English to articulated armpit-belches (note the uses of the hypothetical-voice there).
The third is the most boorish, with a disagreement in the subject-conjugation which changes the meaning of the verb "will". The first "will" is suggestive of a passive-command on "you", (as in nicely telling the person to "will you go home!" i.e. "I will you to go home") and the second use of "will" is the way a passive hope is used on the self, (as in "(you) will yourself to be strong").
"If you will go home you will feel better"
IT`s correct. You use that type of conditional (it is still the first one) when you describe situation/s what is linked with emotion/s, politeness, or very weak unlikly connection for ex. If you will eat apples you will be reach.
There is also a construction ( under conditionals) like "if you went home, you felt better" - but i don`t remember which cond. it is.
