Seqüência de eventos ocorrido no passado - passado perfeito

Para descrever seqüência de eventos que ocorrerem no passado,  se use passado perfeito (past perfect) e verbo de passado (simple past). São exemplos; já tinha terminado estudo antes de começar trabalhar, já tinha comido veneno quando fui transferido para o hospital, etc. O passado perfeito mostra evento que ocorreu primeiro enquanto o passado ilustre evento que ocorreu posteriormente. Exemplos de use são: 

(1) I had finished college when I started to work in 1990.

(2) I had eaten bad food when my friends took me to hospital last summer

(3) I had taken shower before my wife got up from bed yesterday

(4) I had driven my car when I completed 18 years in 2013 

(5) I had watched Globo Television Station before CNN on the day of the attack.

(6) I had gone to toilet when my boss arrived at the office. 

(7) I had given gift to my daughter before she did her 15th anniversary

(8) I had met with my friends before soccer game last every weekend

(9) I had phoned my mother every week when I went to leave in another country.

(10) I had done my homework when my professor requested for it.