Dear Director,
I hope 
this
 letter finds you in radiant spirit and good health, I am writing Linking Words
this
 to inform you about my commitment due to which I will not be able to attend the upcoming party in the Linking Words
college
.
I have an  important examination to appear in. Unfortunately, it is scheduled on the same date as your's Use synonyms
college
 party and Use synonyms
as a result
, I will not be able to attend Linking Words
this
 party. It is a great honour for me to attend Linking Words
such
 an opportunity in my Linking Words
college
 to express my views in front of my colleagues. 
I believe that it will be very difficult for me to miss my paper and attend Use synonyms
this
 honourable occasion. I feel very sorry not to entertain your invitation.
After I am done with my examination. I can deliver my talk in the coming week on any working day as I will be free to give some time for the speech and to meet my Linking Words
college
 fellows.
I was wondering if you could accept my excuse and give me another chance for my speech.
Your's Sincerely
Muhammad IrfanUse synonyms