Answer Check.

They were digging out a drain in the next door garden.

The weather turned quite nasty and it poured with rain.

The garden got so muddy that the digger got stuck.

They got a bigger digger but it got stuck.

They brought a bigger bigger digger on a truck but it got stuck.

The drivers had a meeting and promised they would come back when the rain had gone away.

Two days later the wind blew brisk and dry and the drivers came back.

The mud had hardened round the bigger digger and they couldn't make the wheels turn round.

They managed to start little yellow digger and its wheels turned round.

It was the little yellow digger that pulled the bigger diggers from the mud.

The little yellow digger stayed to finish the drain and make a new driveway that would stay hard in the rain.