increase: To make or become larger in amount or number.
it refers to quantity or intensity as well as size.
The population of this county has increased.
add: To put together with something else so as to increase the
number size, importance.
He added some wood to increase the fire.
(扩大) enlarge: To grown larger or wider.
I want to enlarge this photograph/house.
(放大) magnify: To make something appear larger than in reality, esp. by means of a lens.
You have magnified the peril.
(扩充) amplify: To make large or fuller, esp. give fuller information, more details etc.
to amplify a radio signal/sound.
augment: (fml) To become larger or greater.
It emphasizes the action of addition.
He augmented his income by writing some short stories.
(扩展 扩张) expand: To increase in range scope or volume as well as in size. Iron expands when it is heated.
(加长) extend: To make longer in space or time, to extend a railway.
Can't you extend your visit for a few days.