Forced space

In a text I'm writing, I have this line

is \begin{otherlanguage}{russian}река \end{otherlanguage}\;(rieka),

If I don't put the \; in and put a space in instead, there is
no space after compiling. As it is with \;, there is a space,
but now "(rieka)" is highlighted yellow. How come? What is the
best way to force a space where I have that \; ?
--
db