AO1: US Constitution is codified whereas the UK Constitution is uncodified AO2: This means the US Constitution can be found in one single document specifying the rules determining the political system, whereas the UK Constitution is found in a variety sources AO1: Convention is more regularly used in the UK political system AO2: The codified nature of the US system makes it more difficult to use convention whereas it is more accepted in the UK that conventions can change over time e.g. day/time of PMQ AO1: US Constitution is formally entrenched whereas the UK Constitution is more flexible AO2: This makes the US Constitution more difficult to amend, whereas the UK Constitution can be changed through a variety of methods AO1: Amendments are less frequent in the US due to the formal and lengthy process required AO2: The US Constitution can only be amended if two-thirds of both chambers of Congress and three-quarters of the states agree, whereas the UK can and does regularly change the constitution through statute law e.g. devolution AO1: Human rights are formally entrenched in the US Constitution as the Bill of Rights, but are part of statute law in the UK AO2: This means that certain rights have become embedded in the US political system and culture since the early years, whereas the UK has only comparatively recently added specific protections for human rights to statute law