The following verbs can be regular or irregular: burn can be burned or burnt smell can be smelled or smelt dream can be dreamed or dreamt spell ca...

The following verbs can be regular or irregular:

burn can be burned or burnt
smell can be smelled or smelt
dream can be dreamed or dreamt
spell can be spelled or spelt
lean can be leaned or leant
spill can be spilled or spilt
learn can be learned or learnt
spoil can be spoiled or spoilt