what is the difference between " in twenty years" and " in the twenty years"

[trankhaihoan]

what is the difference between " in twenty years" and " in the twenty years"
who can help me
thank you very much
have a nice day

[Sensible]

'In twenty years' denotes something in the future, eg 'in twenty years time', while using the definitive article 'the' in 'in the twenty years' would be used as a specific reference to a twenty year period that has happened.

Example 1. In twenty years I will be rich. ie; I will be rich in twenty years time.

Example 2. I have never seen that in the twenty years that I have worked here. ie; I have worked here for twenty years now and have never seen that in that specific period of time.

HTH

[BobK]

...but it's not that straightforward; 'in twenty years' can refer to the past. Example: 'In twenty years as a prison warder, I've never had to deal with that sort of riot.' But the period in that case lasts up to the moment of speaking. On the other hand:

During the twenty years ending January 2004, I was a technical writer. Since then I've been a teacher.

b

[Master the TOEIC]

Actually it is fairly straightforward...

"In 20 years" does not have a Relative/Adjective Clause after it. It is a complete Adverb Clause (which may or may not need a comma after it--but it often does).
"In the 20 years" always has a Relative Clause after it! (NOTE: this phrase is almost always talking about a time in the past)

Both can be used to talk about the past and future.

(1) In 20 years, I have not seen a black bear in my neighborhood.
(2) In 20 years, everyone will have a flying car.

(3) In the 20 years since the creation of the internet, more people have learned wanted to learn foreign languages than ever before.
(4) In the 20 years (that) it took me to write my first Sci-Fi novel, many things I write about in the novel have come true.

Sorry if this comes too late to help you trankhaihoan...I just joined the site!

Chris

[BobK]

By it's not that straightforward I meant 'It's not straightforward in that way [one points forwards and one points back]'. Thanks for spelling it out.

b

[Master the TOEIC]

By it's not that straightforward I meant 'It's not straightforward in that way [one points forwards and one points back]'. Thanks for spelling it out.

b

Good point!