日本語をクリックすると英文が表示されます。まずは自分で英語にしてから答え合わせを。
It's a generous offer, but I must decline.
If I had more room, I'd have taken it on.
The timing's bad; it's hard right now.
Unfortunately, that's outside my expertise.
I truly wish I could help, but...
It pains me, but I'll have to pass this time.
Sadly, I can't stretch myself that far.
I'm afraid I can't take responsibility that far.
For various reasons, I have to decline this time.
I'll gratefully accept the thought alone.
I'm glad you asked, but I have other plans.
The timing's off now, so let's revisit it.