Răspuns:
1. - (este exemplul pentru ce ai de facut)
2. My mum has been cooking for three hours.
3. The teams have been playing football for 20 minutes.
4. The headmaster has been speaking for two hours.
5. Bill has been building his house for 6 months.
6. I have been doing my homework for three hours.
Explicație:
Present perfect continuous este format din has/have + been + present participle. Se foloseste cand vrei sa arati ca o actiune a inceput candva in trecut si continua in prezent.
Spre exemplu, subpunctul 2, unde spui ca mama a inceput sa gateasca acum 3 ore si inca nu a terminat, inca gateste.
Fraza "for five minutes" cat si "for three years" sau "since tuesday" sunt duratii ce pot fi folosite cu present perfect continuous. Orice duratie poate fi folosita, atat timp incat actiunea continua pana in prezent.
Sper ca am reusit sa explic cat de cat bine si ca este de ajutor raspunsul.