some improvements
the castles in the middle ages were made of stone not wood because wood would burn easily.
Castles in the early middle ages were motte and bailey castles- a motte was a large mound and a bailey was like a courtyard. These developed into the standard castle with strong stone walls etc.
Someone who did stone work ie building castles
They mostly used blocks of stone.
Most castles in the Middle Ages were built over a span of a decade or more. They were built by masons and carpenters, mostly of stone.
Castles in the Middle Ages were used to keep out enemies.
err stone...? and mortar also wood
No castles have been built since the middle ages
castles were important in the middle ages mainly in 1066 and onwards
The types were mott and bailey. Stone keep castles, Military castles, castles for royalty, rich, lords, and nyone who could afford a castle
Castles were not always stone, but were always fortified for protection. Early on in the Middle Ages, they were made of wood and earthworks; they could be built quickly and inexpensively, but they did not last very long and were easier to defeat than later castles. The later castles were usually made of stone, and were stronger. Where stone was not available, brick was often used, and where a castle was needed in a hurry, the old wood work could still be used. I think the Wikipedia article on castles is a pretty good source of information. There is a link to it below.
motte and bailey castles