Learn English – Past Tense or present perfect: How to correct “I have been to UK three years ago.”

The original sentence is confusing, and not correct English.

1. I went to [the] UK three years ago.
   This says that you arrived in the UK three years ago, but it has no information as to whether you are still there or not. You might have gone for a holiday, or to live.
2. I have been to [the] UK for three years.
   This is incorrect - "in" would be better than "to". It means you arrived three years ago, and have lived there ever since. You may have gone elsewhere for a short time for a holiday or something, but most of your time was spent in the UK.

3. I lived in [the] UK three years ago.
   This one implies that you left three years ago, and had been living there before that for an unspecified duration. It's a little tricky, because if the conversation was about where you were (specifically) three years ago, you could say that sentence, even though you returned last week.

   Oh! Three years ago? I lived in the UK three years ago.

4. I was in [the] UK three years ago.
   This one also has no notion of duration. You may have been there for a day, a week or a year.

Also note that I added "[the]" every time, since it is more common to refer to the United Kingdom (U.K.) and other countries known by their abbreviation (e.g. the U.S.) with the definite article.

As you can see, it depends on what the original sentence meant in context before you can correct it!