Herbal medicine dates back more than 2000 years ago in China.

[Peter Chung]

Could you please tell me whether the following two sentences are grammatically
correct?

1. Herbal medicine dates back more than 2000 years ago in China.
2. The tradition dates back as early as to the 1920s.

Do we need to place "ago" in the first sentence and "to" in the second sentence?

Thanks a lot.

 

[Matthew Wai]

'The custom dates back hundreds of years.'── quoted from http://www.oxfordlearnersdictionaries.com/definition/english/date_2
So it seems that 'ago' can be omitted. I think 'to' should be put before 'as early as'.

Not a teacher.

 

[bhaisahab]

Both "ago" and "to" should be omitted.

 

[Matthew Wai]

Do you mean 'to' should be omitted as long as 'as early as' is used?

 

[Tdol]

Yes- use either as early as or to, but not both.