"Important that John bring/brings" [duplicate]

Solution 1:

Both of your examples are correct. They have different meanings.

It is important that John brings his lunch to school.

In this sentence, brings is indicative and indicates that John does bring his lunch to school, and that fact is important.

Whereas:

It is important that John bring his lunch to school.

In this sentence, bring is subjunctive. The speaker is making an assertion. We don't know whether John brings his lunch to school or not, but the speaker is saying that is is important for him to do so.

Contrary to popular opinion, this is not a matter of personal preference to anyone who has a decent understanding of English. Although people commonly use the indicative instead of the subjunctive, that doesn't make it right.

Which sentence you use depends on the point you are trying to convey. To give a couple of examples where the context makes it more obvious: let's say I want to indicate that a policeman is patrolling the streets well, and people think that's important. I might indicate that he does walk the streets by saying:

It is important that he patrols the streets every night.

On the other hand, it could be the case that a child doesn't like to brush his teeth. He may or may not; we don't know. But I want to say that he should, so I could say:

It is important that he brush his teeth every night.

Solution 2:

OP's second example is correct, but bring is not an "infinitive" verb form - it's the subjunctive, which happens to look the same in modern English.

The subjunctive mood indicates doubt, supposition, uncertainty, and presumes or imagines an action or state. For example:

• It is necessary that he retire
• I strongly recommend that he retire or
• I strongly recommend that he be retired

It's true that many speakers/writers use retires or is retired in these examples, just as they use brings in OP's example. But I don't think I can go so far as @Neil Coffey and say this is a matter of stylistic choice. It may well become so eventually, but as of now I would classify such usage as either informal or a common error (see LATER below).

Having said that, I accept there are a wide range of sentences where the subjunctive mood applies, and strict application of the form is exceptionally rare. An extreme example is...

• If he arrive on time, we will eat before going out.

...which it's hard to imagine anyone endorsing today, even though it's "correct". Careful speakers would probably recast the sentence (still in the subjunctive) as...

• If he were to arrive on time, we would[could] eat before going out.

...but again, many people would simply use the "incorrect" form...

• If he arrives on time, we will eat before going out.

TL;DR: The subjunctive is not yet dead. Long live the subjunctive! (to those who didn't spot it, live there is in the subjunctive, and as of today, few would replace it with lives).

LATER: @Jez astutlely and clearly makes the point that the first sentence is quite capable of being understood to have a related but significantly different meaning to that intended here. Another good reason not to let the subjunctive die – why should we lose the ability to make that distinction?