Spoilt vs spoiled

The usage of these words have always confused me. Can they be used interchangeably?

Yes, it's the same example as learned vs learnt. They are the past simple form of the same infinitive verb. The only difference is if it is British English, or American English. The ones ending on "t", are usually the British version. 

Mai wrote:

Yes, it's the same example as learned vs learnt. They are the past simple form of the same infinitive verb. The only difference is if it is British English, or American English. The ones ending on "t", are usually the British version.

Oh really? Thanks Mai, cos I was thinking they were used differently when someone attempted to correct me.

Sometimes semantic as well as regional differences in use may occur. To light - lighted - lighted

To light - lit - lit

Whereas more and more Americans use exclusively the form 'lighted', the British preserve both forms (lit - meaning set something on fire, e.g. candle, grill; lighted - regarding illumination). 

English is just so complicated!