I just discovered the I shoudn't be using \\ as paragraphe separator, so I replaced it with \par.
I wanted also a slight space between paragraphes so I set \setlength{\parskip}{1em} and it's lovely but Latex put an extra space litteraly everywhere! So my table of contents is spread through 5 pages, and what is worst my \expex exemples are also very wide.
How can I control it? Is there a command that allows me to have this blank space in texte only?
\paron the end of paragraph. It is sufficient to put blank line between them. For more sophisticated control ofparskipsee link which provide Alan Munn. – Zarko Aug 05 '15 at 19:20\parskip=1emis huge, and it should be arubber lengthwith aplusand aminuspart. Furthermore, there is a side-effect on thelist environmentsand thetable of contents, so you should either load theparskippackage, or use one of thekomascriptclasses. – Bernard Aug 05 '15 at 19:24