I am inputting TIPA code for some African languages. I encountered a problem with inputting floating tone. The floating tone is a high tone (\') or a low tone (`) over a space instead of over any symbol.
If I input \'{ } or `{ }, the tone symbols drop to the bottom of the line, while they are supposed to be above the space. How can I deal with this problem? Thanks!
\documentclass{article}
\usepackage{tipa}
\begin{document}
\begin{IPA}
aa\'{ } aa`{ }
\end{IPA}
\end{document}

\documentclass{...}and ending with\end{document}. – DG' Feb 25 '16 at 14:23