next

[mengta]

I'll be there next week.
I'll be there the next week.
next year will be difficult.
the next year will be difficult.

what's the difference?

[Tdol]

I wouldn't use 'the next' in either of those. The next is used in a sequence.

[HotWombat]

I'll be there next week.
I'll be there the next week.
next year will be difficult.
the next year will be difficult.

what's the difference?

If we replaced the word 'next' in sentences two and four with the word 'following', would the four sentences be acceptable then.

[RonBee]

I'll be there next week.
I'll be there the next week.
next year will be difficult.
the next year will be difficult.

what's the difference?

If we replaced the word 'next' in sentences two and four with the word 'following', would the four sentences be acceptable then.

That would depend on context. If you have, for example, indicated a specific week then "the following week" means the week that comes after that one.

:)

[queenmaabd]

This type of structure is also used a lot in reported speach. When we report the following statement

John said, "Jane will come next week".

We would say,

John said that Jane would come the next week.

In this case, it doens't mean this coming week, but the week after the one they were living at that time.