かたがたWhile also fulfilling a formal social purpose
This construction formally combines a courteous social purpose—such as offering thanks, an apology, or a greeting—with a visit, call, report, or message made on the same occasion.
One occasion, two purposes
The noun before かたがた names a courteous purpose. The action afterward is the visit, call, report, or message through which that purpose is also fulfilled. Both belong to one particular occasion, not to two continuing activities.
Typical formal occasions
就任のご挨拶かたがた、主要な取引先を訪問いたしました。
I visited our main business partners to introduce myself upon taking up my new post.
Analyze先日のお礼かたがた、近況をご報告申し上げます。
Along with thanking you for the other day, I would like to update you on how things have been.
Analyzeお見舞いかたがた、病院へ伺いました。
I went to the hospital to pay a visit and offer my good wishes.
Analyzeお詫びかたがた、今回の経緯をご説明に参りました。
I have come to apologize and explain how this situation arose.
AnalyzeChoosing among similar expressions
かたがた is the formal, courteous choice for a socially recognized purpose on one occasion. がてら is less formal and commonly adds another action to an outing or activity; ついでに is the ordinary choice for taking advantage of an opportunity; and を兼ねて combines two purposes more broadly without requiring a courtesy formula. かたわら is different again: it describes an ongoing secondary role or activity rather than one formal occasion.
More examples
ご報告かたがた、関係資料をお届けに参りました。
I have come to give you an update and deliver the relevant documents.
Analyzeお礼かたがた、改めてお電話を差し上げました。
I called again to express my thanks.
Analyze帰国のご挨拶かたがた、恩師のお宅を訪ねました。
I visited my former teacher to greet them after returning to the country.
Analyzeお詫びかたがた、責任者が先方を訪問いたしました。
The person in charge visited the other party to offer an apology.
Analyze退院のご報告かたがた、先生の研究室へ伺いました。
I visited the professor’s office to report that I had been discharged from the hospital.
Analyze
Choose a socially appropriate purpose
This is not a general way to say that you did two things at once. The first purpose normally belongs to a recognized act of courtesy, and the rest of the sentence describes an action that can naturally carry it out. Formal wording in the rest of the sentence is therefore common.