Tip: See my list of the 
MostThe present subjunctive is a really easy mood to use: it is always identical to the infinitive in English, and speakers of other Germanic and Romance languages should be familiar with the concept (it is called “conjunctive” in some languages).
The present subjunctive is used after phrases like “It is important that”, “I insist that”, or “It is necessary that”, for example:
When you think about it, the red examples do not make much sense. Nevertheless, some speakers (especially British) tend to use the indicative mood (the present tense) instead of the present subjunctive there. This should be avoided in formal writing because it may lead to misunderstandings. Compare:
It is important that he has a computer. (indicative)
The former sentence says that he is required to have a computer. The latter, on the other hand, literally means that he already has a computer, and this fact is important.
Of course, the subjunctive differs from the indicative only in the third person singular. In all other cases, you have to recognize the intended meaning from the context. The sentence
can mean two different things, depending on whether “have” is in the subjunctive or the indicative mood.
In spoken English, the subjunctive is commonly replaced by another construction:
It is essential for him to come early. (common in speech)
In British English, the present subjunctive is often replaced by “should + infinitive”:
This construction is less common in American English and may be considered unnatural by some, so I recommend sticking to the subjunctive.
