The inauguration of the new president of the USA takes place on 20th January in Washington DC. Here are a few expressions you might find in the press at this time. Some are ‘good friends’ as opposed to 'false friends'.
Inauguration – the formal admission of someone into office (usually political but not necessarily)
Incumbent – the current holder of the position. Obama is the incumbent president.
Predecessor – the person who held a position before the current holder. Barak Obama’s predecessor was GW Bush.
Successor – the person who takes over a position from someone else. Obama’s successor is DJ Trump.
The oath of office – An oath is another word for ‘promise’ and in this case, the new president and vice-president promise to uphold the American Constitution.
To swear in – to officially and publicly administer an oath. A representative of the nation swears in the president at the inauguration ceremony.