Visit restrictions are different for Canadians & British. Canadians & a number of others can stay, visa free, for 180 days a year.
As has been pointed out the OP can stay, visa free, for 3 months then a relatively easy to get extension must be obtained for a longer stay.
I find it a little odd that the British only get 3 months yet we in Bermuda, a British colony, have 6 months like the Canadians.
Must be in appreciation for way back during your war of independence when we stole gunpowder from a British fort here & took it out to American ships which took it & used it against the British.