Used to introduce unfortunate or disappointing information in a formal or sincere way.
“Regrettably, we won't be able to refund the full amount.”
“Regrettably, I must decline the invitation due to a prior commitment.”
This word is a slightly more formal alternative to 'unfortunately' and works well in Task 6 when your response needs a more serious or apologetic tone, such as when declining a request. Using varied vocabulary like this can boost your vocabulary score.
Synonyms: unfortunately, sadly, with regret