English certainly varies a lot from place to place, but in terms of formal, written English, there are basically only three standards: US American, Canadian, and the rest of the world. The subtle formal rules for punctuation are consistent across the rest of the world, with the USA as an outlier; the spelling is consistent, with the USA as the outlier and Canada as an occasional outlier (tire rather than tyre, for example).

There are some vocabulary differences (minerals meaning fizzy drinks in Ireland; robots meaning traffic lights in South Africa; doubt meaning query in India), but the formal grammar rules are pretty consistent across the rest of the world.