Jawaban:

1.We have worn black socks since Wednesday.

2.Rina has won the singing competition.

3.The game hasn't started yet. ​

Penjelasan:

Rumus present perfect tense adalah:

subjek + have/has + verb 3

HAVE dipakai jika subjek kalimat adalah: I, You, We, They. Termasuk di They adalah plural noun (kata benda jamak) misalnya Parents, Students, Two balls, The people, dst.

Contoh:

I have booked the flight.

All students have submitted their homework

HAS dipakai jika subjek kalimatnya adalah He, She, It. Termasuk di sini adalah semua singular noun (kata benda tunggal) atau uncountable noun (kata benda yang tak bisa dihitung), misalnya My father, your daughter, a dog, his cat, milk, water, the government, my education dll.

Contoh:

The milk has passed its expiry date.

My father has cleaned his bike

The government has increased gasoline price.

Semoga bermanfaat.