Emphasis on something negative and word inversion caused by it

If we want to make something sound stronger and more emphatic in written English, we use negative words:

• seldom
• rarely
• never
• neither
• no sooner (than)
• not only

These words are used at the beginning of the sentence with inversion, i.g. the word order of a question.

• He has never known anything about them. - Never has he known anything about them.
• The dolphins are not only beautiful but they are clever as well. - Not only are dolphins beautiful but they are clever as well.

We can also use emphatic inversion in third conditional sentences. We drop if in the inverted form. These structure is common in both formal and informal language:

• If the weather had been fine, we should have played outside. - Had the weather been fine, we should have played outside.
• If you had been free, I should have come to see you. - Had you been free, I should have come to see you.

In both formal and informal language, we can use these structures to put more emphasis on some words:

• She is interested in this book. - It's a book that she is interested in. (We put emphasis on book)
• I only need some paper to print this information. - All I need is some paper to print this information. (We put emphasis on paper)