How to typeset subscript in usual text mode?

Question

It's easy to make subscripts in math mode: $a_i$.

How do I make a subscript outside math environment, like_this?

Answer 1

LaTeX provides \raisebox{<len>}{<stuff>} (based on TeX's \raise) which raises (and boxes) <stuff> by <len>. A negative <len> drops the contents:

\documentclass{article}
\begin{document}
It's easy to make subscripts in math mode: $a_i$.

How do I make a subscript outside math environment, 
like\raisebox{-.4ex}{\scriptsize this}?
\end{document}​

Answer 2

If you use the $\text{}$ version and you have selected a different font (other than roman serif) then $\textnormal{}$ matches the font of the document. If you are using the default fonts, \text{} will work great.

Answer 3

If you don't want to use additional packages you can use the following syntax:
like $_{\text{this}}$.

Alternatively, you can define a command \textunderscript in the beginning of your document:

\newcommand{\textunderscript}[1]{$_{\text{#1}}$}

Answer 4

Since I've always been bugged by the fact that LaTeX's sscripts need math mode (setting normal text inside math mode have issues with LuaTeX's directionality), motivated by this question, I "stole" the subscript/superscript code from ConTeXt which is set entirely in text mode, with quick hacks to get it work with plain TeX (needs pdftex/luatex though), it is here for now, if there is interest may be it can be turned into some package.

Answer 5

In ConTeXt, you can write

like\low{this}

Answer 6

Note that \textsubscript enters math mode as well. This might produce problems in PDF strings where math is not allowed, for instance in bookmarks. If you used hyperref and simply used \textsubscript in a section heading, hyperref would complain about the math shift. The command \texorpdfstring comes to the rescue:

\documentclass{article}
\usepackage{fixltx2e}
\usepackage{hyperref}
\begin{document}
\section{\texorpdfstring{like\textsubscript{this}}{like this}}
\end{document}

That applies to math and math symbols in sectioning headings of course as well.

Answer 7

This is included in the fixltx2e package:

\documentclass{article}
\usepackage{fixltx2e}

\begin{document}
like\textsubscript{this}
\end{document}

Interestingly (?), there's a \textsuperscript command already in LaTeX.

This is included already in the KOMA-Script bundle. If you want to typeset chemical formulas, have a look at the mchem package.

(Thanks to Caramdir for those last two.)