Find the odd words in the lines. a) cottage, house, bridge,

a) cottage, house, bridge, building.
The odd word in this line is BRIDGE because other words describe buildings (constructions).

 b) street, monument, square, road.
The odd word is MONUMENT. Other words describe parts of the city - road, street, square. They can be used as address. 

d) short, talk, tasty, big.
TALK is the odd word. Other words are used to describe signs of an object. But talk is a verb.

c) nicer, hotter, warmer, coldest.
The odd word is COLDEST, other words are used in another form. This rule is called Degree of Comparison.