You can train them by dropping them on a completed hut and they will start 'fixing' it. This is the same as in VV1 and VV2. If they are successful they will gain some building skill. Once they reach trainee level they can help out with pushing the statue.
Another way for villagers to gain building skills is by exercise; there is a potion you can use that will set them excercising.
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To err is human; to arr is pirate.