Example using gb4e without gloss line

Question

Using gb4e I can leave off the free translation line of a three-line format, but is there a way to leave off the gloss line? I am using examples from linguists who gave only the source language and the free translation in their original publications.

In the MWE below, the example01 and example03 will compile, but not example02. Is there a way to have the source text and the free translation, without the gloss line?

I could simply have an unnumbered example, but for the sake of coding consistency with examples, I'd like to continue using \gll and \glt.

\documentclass{article}
\usepackage[margin=1in]{geometry}
\usepackage{gb4e}
\begin{document}
In example (\ref{citko21}) we can see some data from Polish.
   \begin{exe}
   \ex\label{citko21}
   \begin{xlist}
%example01(all three lines)
   \ex \gll One     Jan lubi e      a Maria podziwia e?\\
       who.ACC Jan likes e.ACC and Maria admires e.ACC\\
       \glt `Who does Jan like and Maria admire?'
%example02(lacks gloss line)
%compiling either fails at this point or this example is just skipped
  \ex \gll Two     Jan lubi e      a Maria podziwia e?\\
      \glt `Who does Jan like and Maria admire?'
%example03(lacks free translation line)
  \ex \gll Three     Jan lubi e      a Maria podziwia e?\\
           who.ACC Jan likes e.ACC and Maria admires e.ACC\\
\end{xlist}
\end{exe}
\end{document} 

Answer 1

Since the \gll macro expects two lines, you can't do exactly that, but you can just leave out the \gll (and the final \\) and use \glt by itself:

\ex  Two     Jan lubi e      a Maria podziwia e?
\glt `Who does Jan like and Maria admire?'

One downside of this solution is that if you add a grammaticality judgement to the \ex the glt line won't line up properly; it will left align with the * instead of the first word of the example.

To solve this, you can wrap the \glt line in an unnumbered example \sn :

\ex[*]{  Two     Jan lubi e      a Maria podziwia e?}
\sn[]{\glt `Who does Jan like and Maria admire?'}