"Ydw, dw i wedi mynd i'r swyddfa."

Translation: Yes, I have gone to the office.

[drowswell]

I put "Yes, I have been to the office" by accident and it was marked correct. Are these not two different meanings?

[ibisc]

Yes. The spurious answer has now been deleted.

• Dw i wedi bod i'r swyddfa. - I have been to the office.

[owenblacker]

Why would "I went" be wrong, rather than "I have gone"?

[shwmae]

Es i = "I went"

Dw i wedi mynd = "I've gone"

[lizmat115]

Simple past (went) is often used with a word or phrase that indicates when you did something. I went to the office yesterday. Present perfect is usually used without being specific about time. I have gone to the city. It sounds a bit odd in English because if you have gone, you aren't here, so can't be talking to the person, except maybe on the phone or in a note.