After some verbs you can use an infinitive (vorm I in present simple)as well as a gerund (ing form) without a difference in meaning.
Start
I started working on my paper yesterday afternoon.
I started to work on my paper yesterday afternoon.
Begin
I began thinking I could fail my driving test when I didn’t stop at the traffic light.
I began to think I could fail my driving test when I didn’t stop at the traffic light.
Continue
He continued singing a popular song.
He continued to sing a popular song.
Attempt
They attempted extinguishing the fire
The attempted to extinguish the fire