Past perfect simple czy Past perfect continuous

[Gość: jolka23]

Proszę o sprawdzenie:
1.I had often thought of starting up in business on my own but never
had the courage to go it alone.
2.The firm had been making cars for many years before they decided
to diversify and start manufacturing cycles as well.
3.My grandparents had been never travelling abroad before they went
on their trip to Italy.
4.I had walked Spanish for seven years before I made the decision to
carry on with it at university.
5.I phoned the dentist's surgery as soon as I realised that I had
forgot my appointment.
Z góry dziękuję.