YOU SAID:
my summer holidays has officially started
INTO JAPANESE
私の夏休みは正式に始まった
BACK INTO ENGLISH
my summer vacation officially began
INTO JAPANESE
私の夏休みが正式に始まった
BACK INTO ENGLISH
My summer vacation has officially begun
INTO JAPANESE
私の夏休みが正式に始まりました
BACK INTO ENGLISH
My summer vacation has officially begun
Come on, you can do better than that.