'It is essential that he be present.' Not 'is present' — 'be present', with no -s, no tense marking at all, even though 'he' is singular. This is the subjunctive mood: a special base-form verb used after certain expressions of necessity, recommendation, or demand — even in the present tense, even with he/she/it.

It appears after verbs like suggest, recommend, insist, demand, propose, and after expressions like 'it is essential/important/vital that'. Compare informal spoken English, which often uses 'should': 'I suggest that he should leave' (common, less formal) vs the more formal subjunctive: 'I suggest that he leave.' Both are correct; the subjunctive signals a more formal, careful register. 🔊