It is not necessary to say that you can't buy anything. If your forgot your wallet, then you will not be buying anything. You could add the phrase, "As I have no means of paying, unfortunately I'm afraid I cannot buy anything," if you like, but it is really superfluous.
何も買うことができないと言う必要はありません。財布を忘れてしまったら、何も買うことができないのはすぐわかりますから。
"As I have no means of paying, unfortunately I'm afraid I cannot buy anything,"というフレーズを追加することもできますけど、やはり余計ですね～。
I unfortunately can't buy anything anymore, I forgot my wallet at home.
I feel so silly! I forgot my wallet at home and now I can't buy anything.
>I unfortunately can't buy anything anymore, I forgot my wallet at home.
>I feel so silly! I forgot my wallet at home and now I can't buy anything.
Both phrases are clearly indicating that you not going to buy anything anymore and the reason is that you forgot your wallet.
I unfortunately can't buy anything anymore, I forgot my wallet at home.
I feel so silly! I forgot my wallet at home and now I can't buy anything.
どちらも財布を忘れたので、何も購入することができないことを意味する表現です。
I went shopping without my wallet so couldn't buy/purchase anything
I couldn't buy/purchase anything when i went shopping as i forgot my wallet
If you want to buy something you can also use the word 'purchase' so to explain you left your wallet when you went shopping you could say 'I went shopping without my wallet so couldn't buy/purchase anything' this explains it well
「買う（buy）」は、'purchase'とも言えます。
なので、財布を忘れて買い物に行ってしまったことは次のように説明できます。
'I went shopping without my wallet so couldn't buy/purchase anything'（財布を持たずに買い物に行ってしまったので、何も買えませんでした）
これでうまく説明できます。
I need to get my wallet, Can you hold these products for me?
Forgetting your wallet is an accident and most people will be helpful. If your wallet is nearby (for example your car outside), you could excuse yourself politely and return to make the payment.
イギリス 
日本 
南アフリカ 
オーストラリア 
