# Why this " (one symbol) works as one double quote as well

According all the tutorials I could found, I need to use

 + ''    (two single quote symbol)


to produce the double quote. However, it seems that

 + "     (one symbol)


works as well.

Is this supposed to be? If so, why none of tutorials mention this?

• There are various ways to create the quotes (I personally use the csquotes package). Your second solution will not work with \usepackage[T1]{fontenc} so it is not recommended. ” will work if you use the correct inputenc option. Jun 26, 2013 at 12:01
• All tutorials explain that the closing double quotes should be input as '' and they are right. Inputting " has unpredictable output. Jun 26, 2013 at 12:13
• there are technical reasons for this ...'' stuff, but they're buried in the history of knuth's font mechanisms. much of the time, we don't use knuth's original font mechanisms, nowadays, but the silly typing rules have persisted. :-( ... and the tutorials probably ought to mention it, but the authors probably thought it wasn't worth mentioning. Jun 26, 2013 at 16:47

The character " seems to produce the right quotes, but this is not really true. There are two cases.

## OT1 encoding

Look at what happens with these apparently identical inputs:

\documentclass{article}

\begin{document}

this ends a quotation." And here text starts again

this ends a quotation.'' And here text starts again

\end{document}


Can you spot the difference? In the first case a normal interword space is produced after the quotes, in the second case there's an extended space, which is what's expected after a period (preceding or not the quotes), of course assuming "non French spacing".

## T1 encoding

Add \usepackage[T1]{fontenc} to the input above and you get

The problem with the extended space seems to have disappeared, but this is not true: the fact is that the glyph produced by " is wider than the curly double quotes. But it's even worse than before, because now the quotes are straight and not curly, which is unacceptable from a typographycal point of view.

## Conclusion

All tutorials recommend '' for producing closing double quotes and they are fully right.

• Why don't you get the sentence-ending space when you type ... quotation." And ...? Just wondering.
– MSC
Apr 22, 2014 at 16:00
• @MSC Because the space factor code of " is not zero. One could set it to zero, of course. Apr 22, 2014 at 16:01

Thanks for pointing it out. Here's one MWE to illustrate the problem.

\documentclass{article}

\usepackage[T1]{fontenc} % for latex
% \usepackage{fontspec} % for xetex
\begin{document}
{\Huge "hello"\par}

{\Huge hello"\par}

{\Huge hello''\par}

\end{document}


The following is the output.

If we don't use fontenc or fontspec, (which is highly recommend against), all three of them give correct result for right quote, shown following:

# Conclusion

Use what's mentioned in all the tutorials, and include fontenc or fontspec.

• Does the first one give a correct result for you? Jun 26, 2013 at 14:42
• @karlkoeller What do you mean by "first one"? The two images for corresponding to two use cases, the one with fontenc and the one without fontenc. Jun 28, 2013 at 13:23
• The first one of the second image. Is it a wanted behavior? Jun 28, 2013 at 14:06
• @karlkoeller obviously not - but the question implies that Albert is aware of that :) so I think this is just an example for demonstration purposes Jun 29, 2013 at 18:24
• @cgnieder Yes I know, I was only kidding :-) Jun 30, 2013 at 6:07