YOU SAID:
I did the deed last night
INTO JAPANESE
私は昨夜証書をしました
BACK INTO ENGLISH
I gave a certificate last night
INTO JAPANESE
昨夜証明書をあげました
BACK INTO ENGLISH
I gave you a certificate last night
INTO JAPANESE
昨夜あなたに証明書をあげました
BACK INTO ENGLISH
I gave you a certificate last night
You've done this before, haven't you.