# Paragraph numbering (lineno for paragraphs)

How can I add margin numbering for paragraphs? It should be alternating (left and right) for odd and even pages. So basically like lineo with the switch option but for paragraphs instead of lines.

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– user11232
Mar 7 '15 at 15:33

Shorter and raw

\documentclass[twoside]{article}
\usepackage{lipsum}
\newcounter{mypara}
\setcounter{mypara}{0}

\begin{document}
\everypar{\refstepcounter{mypara}
\ifodd\value{page}
\marginpar{\themypara}
\else
\marginpar{\makebox[\marginparwidth][r]{\themypara}}
\fi}%
\lipsum[1-100]
\end{document}


This uses \everypar (exploiting David's answer at Why does \everypar not work?) to make "something" happen every paragraph. In this case, the "something" that happens is a \tabto to the margin, where the paragraph number is laid, followed by a return to the original position. I use an everypage hook to toggle the marginal location with each page.

I wrap it all in an enumpars environment, so that you can turn it on and off at will.

\documentclass{article}
\usepackage{lipsum,tabto,everypage}
\def\TabMargLeft{-.5in}
\def\TabMargRight{\dimexpr\textwidth+.5in\relax}
\def\TabMargPos{\TabMargRight}
\gdef\TabMargPos{\TabMargRight}\else%
\gdef\TabMargPos{\TabMargLeft}\fi}
\newcounter{parcount}
\let\oldep\everypar%
\newenvironment{enumpars}
{\newtoks\everypar%
\setcounter{parcount}{0}%
\oldep{\the\everypar\stepcounter{parcount}%
\tabto*{\TabMargPos}\makebox[0pt]{(\theparcount)}\tabto*{\TabPrevPos}}%
\par}{\global\let\everypar\oldep\par}
\begin{document}
\begin{enumpars}
\lipsum[1-5]
\end{enumpars}
\lipsum[6-8]
\begin{enumpars}
\lipsum[9-14]
\end{enumpars}
\end{document}


• It says \let\oldep\everypar in the beginnig but \let\everypar\oldpars at the end -- is this a typo? Isn't the idea to save whatever it is \everypar and reset it to this value after the enumpars-environment? Or am I just misunderstanding what you are doing here? Aug 16 '21 at 13:04
• @Florian Yes, thank you for detecting that typo. I will fix it. Aug 16 '21 at 13:39
• Unfortunately I am still having an issue with this solution: When I add another evironment, say \begin{enumerate} after enumpars has been used I get "Something's wrong--perhaps a missing \item." Using environments within enumpars works fine and the paragraphs are even counted properly. Aug 18 '21 at 12:03
• @Florian Thanks again for noting that. I had to make the final \let of enumpars be global in order to reach outside of the environment. Thus, the closing part of the environment now reads, {\global\let\everypar\oldep\par} Aug 18 '21 at 12:08
• This must be getting on your nerves... But you wouldn't have an idea why \usepackage[cam, info]{crop} interferes with the counting, would you? Aug 19 '21 at 10:32