1. They began to learn French two years ago. -> They have...

They have learnt French for 2 years 

Cấu trúc :

S + started / began +  V-ing / to V + 1 khoảng TG + ago

= S + have / has + VPII + for + 1 khoảng TG

Hoặc

S + started / began +  V-ing / to V + when + S + V-ed /V2

= S + have / has + VPII + since + 1 mốc TG