learn，have，write，start，call
（1）I

learned

learned

to ride a bike when I was four years old．
（2）Students usually

start

start

learning English in primary schools．
（3）They

had

had

a big party to celebrate （慶祝） the harvest last October．
（4）Professor Li stopped

writing

writing

after he had a heart disease．
（5）I

called

called

Lucy last night，but she was not at home．