1. to do sth from scratch: Our experiment failed, so we had to do everything again from scratch.
2. up to scratch (informal : The hotels we were recommended weren’t up to scratch and we decided to look for something better.
3. to scratch one's head: The decision was very sudden and left many cabinet members scratching their heads.
4. to scratch a living: I don’t know how they are scratching a living with so many kids andjust one breadwinner.
5. to scratch the surface: I can’t say that I know the country well, I have only really scratched its surface.
6. to scratch around (for sth : Everyone did their best to scratch around for the lost document but in vain — it was never found.
7. to scratch one's plans: It began raining heavily and we scratched our plans for the weekend.
8. to scratch together: How much money have you managed to scratch together?
9. Scratch my back and I'll scratch yours: Who knows, I may be able to help you some day, too. You know what they say — scratch my back and I’ll scratch yours.