# LaTeX: The Space Between Words [duplicate]

I read the book The Not So Short Introduction to LaTeX, and found this line:

LaTeX: Tilde '~' generates a space that cannot be enlarged and...

It seems that the tilde make the space smaller when I compare Mr.~Smith and Mr. Smith.

Question 1: When shall I generate a space that cannot be enlarged?

In addition, same in the section The Space Between Words, there is a line:

If a period follows an uppercase letter, this is not taken as a sentence ending,...

However, no matter uppercase or lowercase I follow a period, I cannot find something different.

Question 2: Can anyone show me an example?

Thirdly,

The command \@ in front of a period specifies that this period terminates a sentence even when it follows an uppercase letter.

Similarly, for those two lines, I cannot find any difference.

I am new to Latex\@. And you?

I am new to Latex. And you?

## marked as duplicate by Sverre, Sigur, Svend Tveskæg, Martin Schröder, user13907 Jul 25 '15 at 13:01

• The ~ (tilde) is mostly a fixed and non-breakable space. -> Donald~E.~Knuth – Johannes_B Jul 25 '15 at 12:05
• Have you tried out the examples to be found in lshort? – Johannes_B Jul 25 '15 at 12:07
• It depends on (unknown for us) packages that you are using. The behaviour of distance after a dot is controlled by \frenchspacing/\nonfrenchspacing. Try to use this sitch to see the differences. – Kola B. Jul 25 '15 at 12:08
• Question 1 a duplicate of tex.stackexchange.com/questions/15547/…. Question 2 a duplicate of tex.stackexchange.com/questions/2229/…. – Sverre Jul 25 '15 at 12:11
• you have xxx ~yyy which is two spaces a normal   and an additional ~ you just want xxx~yyy if you are using ~. – David Carlisle Jul 25 '15 at 12:27

Regarding the second question: The \@ isn't needed with words ending with lowercase letters. LaTeX assumes then anyway that the period is a end of sentence marker.

\documentclass{article}
\begin{document}

I am new to LateX\@. And you?

I am new to LateX. And you?

I am new to Latex. And you?

I am new to Latex.\ And you?
\end{document}