This week I'm free on Wednesday but not on Monday.
"今週水曜日はいいですけど月曜日はダメです"
- This week I'm free on Wednesday but not on Monday.
free = 空いてる
I'm free on XXXXX but not on XXXX
I'm not free on XXXX but I am on XXXX.
例文：
(今月の)18日21日25日はいいけど、17日と23日はダメです。
(This month,) I'm free on the 18th, 21st, and 25th but not the 17th and 23rd.
逆
I'm not free on the 17th or the 23rd but I am on the 18th, 21st, and 25th.
Will you tell me when you are available on the condition that this Wednesday is OK but Monday not.
Will you tell me when it is convenient for you on the condition that this Wednesday is OK but Monday not?
This Wednesday is OK with us, but Monday not. Will you tell us your availability based on it?
相手に対して予定を聞く状況を踏まえての疑問文です。
Will you tell me when you are available on the condition that this Wednesday is OK but Monday not?
今週の水曜日はＯＫですが、月曜日はダメという条件のもとに空いてる時を教えてもらえますか？
Will you tell me when it is convenient for you on the condition that this Wednesday is OK but Monday not?
今週の水曜日はＯＫですが、月曜日はダメという条件のもとに都合を教えてもらえますか？
次は２文に分けて会話体で分かりやすく表現してみました。
This Wednesday is OK with us, but Monday not. Will you tell us your availability based on it?
今週の水曜日はＯＫですが、月曜日はダメなのですが、それを基準に空いてる時を教えてもらえますか？
I can do Wednesday this week, but I can't do Monday.
「今週水曜日はいいですけど月曜日はダメです」は英語で「I can do Wednesday this week, but I can't do Monday.」と言います。「I can't do Monday」より「Monday is no good」でも使えます。日にちの場合なら曜日を入れ替えて「the 24th」（24日）や「the 1st」（1日）の「the」が必要です。
28日はいいですけど30日はダメです。
I can do the 28th, but I can't do the 30th.
アメリカ合衆国 
日本 
カナダ 
