Indent first paragraph only once

Question

I'm writing a document in English which includes an abstract in Spanish. In Spanish the first paragraph of a chapter should be indented, while in English shouldn't.

If I use indentfirst package, all first paragraphs in the document would be indented.

How can I indent a first paragraph only once, i.e., without affecting other first paragraphs in the document?

EDIT: I only want to indent the first line of paragraphs. \indent doesn't do the job, maybe because it's overridden to not indent first paragraphs.

Answer 1

\indent does not work as the code LaTeX inserts to remove the indentation after a section heading really does remove the indentation box, even if added explicitly.

Try

\section{hhh}
\hspace*{\parindent}aa bb ccaa 

Answer 2

Add to the code executed when entering Spanish what's done by indentfirst; we do also the converse, when exiting Spanish.

\documentclass{article}
\usepackage[spanish,english]{babel}
\makeatletter
\let\original@afterindentfalse\@afterindentfalse
\addto{\extrasspanish}{\let\@afterindentfalse\@afterindenttrue}
\addto{\noextrasspanish}{\let\@afterindentfalse\original@afterindentfalse}
\makeatother
\usepackage{lipsum}
\begin{document}
\begin{otherlanguage}{spanish}
\section{\abstractname}
\lipsum[2]
\end{otherlanguage}

\lipsum[3]
\end{document}

Answer 3

You could set up a new environment if you would like to indent a full paragraph.

\newenvironment{myindentpar}[1]
 {\begin{list}{}
         {\setlength{\leftmargin}{#1}}
         \item[]
 }
 {\end{list}}

Then you could call this environment by

\begin{myindentpar}{3cm}
text text text...
\end{myindentpar}

In case you just want to indent a single line I would suggest the \indent command.

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