If you are efficient you work well without wasting time or energy.

As he was efficient he was promoted.

If something is effective, it has the desired result.

Else can mean ‘other’ or ‘more’ after words like somebody / someone / something / somewhere / anybody / anyone / anything / anywhere / everybody / everyone / everything / everywhere / nobody / no one / nothing /nowhere etc.

The words eastern, western, northern and southern are used to talk about rather indefinite areas. The words east, west, north and south are used to talk about more clearly defined places.

Go is used before a number of adjectives to talk about changes. This is common in an informal style.
Go, for example, is used to talk about changes of color. This usage is common in British English.
Examples are: go brown, go green, go white, go black, go blue etc.

Take can be used as the opposite of give. It means ‘gain possession of’, ‘receive’, ‘obtain’ and ‘remove’.

Too is an adverb. It can modify verbs, adjectives and other adverbs.

Too has a negative meaning. It means ‘more than is necessary or desirable’.

Dead and deadly

Dead is an adverb used in expressions like dead right, dead certain, dead slow, dead straight, dead sure etc. It means ‘exactly’, ‘completely’ or ‘very’.