Complete compound structures

In compound structures, words are often omitted for economy:

Such omissions are perfectly acceptable as long as the omitted word is common to both parts of the compound structure, as who is in the example sentence.

Sometimes omitting a word results in an ungrammatical sentence because the omitted word is not the same in both parts of the compound structure. In such cases, you must put the word back in.

The word who must be included because whom . . . live in our community is not grammatically correct.

Has . . . accept is not grammatically correct.

Believe . . . by is not idiomatic English.

Exercises:

Needed words 1

Needed words 2

Needed words 3

Needed words 4