本日はお招きいただき、誠にありがとうございます。 — Thank you sincerely for inviting me today. (Cultural · Communication, Formal — to stranger, JLPT N4)

そうですね……おっしゃる通りかと思います。

Let me think about that... (intentional pause) I believe you're right.

Formal to Superior · JLPT N4

少し難しいかもしれません……

That might be a little difficult... (polite way of saying 'no' or 'I cannot do this')

Formal to Superior · JLPT N4

（うなずきながら）ええ、ええ。なるほど、そうですか。

(nodding) Yes, yes. I see — is that so.

Polite to Colleague · JLPT N4

ご都合はいかがですか？

How are you situated? / Would that work for you? (a polite opener that gives the other person room to decline)

Formal — to stranger · JLPT N4

まだまだです。これからもっと精進しなければなりません。

I still have a long way to go. I need to work much harder from here.

Formal to Superior · JLPT N4

おかげさまで、なんとかうまくいきました。皆さんのご支援のおかげです。

Thanks to everyone's support, things worked out somehow. It's all thanks to all of you.

Formal to Superior · JLPT N4

少し考えさせてください。

Please let me think for a moment.

Universal · JLPT N4

事前にご意見をお聞かせいただければ幸いです。

I would be grateful if you could share your thoughts in advance.

Formal to Superior · JLPT N2