

\begin{table*}[h!]
\begin{center}
\small
%\begin{adjustbox}{max width=\linewidth}
    \begin{tabular}{lrllllrl}
\toprule
 %\multicolumn{6}{c}{\bf Declension Classes. Class size and gender contained in the classes are provided.} \\ 
    \multicolumn{4}{c}{\bf German} %& \multicolumn{3}{c}{\bf Arabic} 
    & \multicolumn{3}{c}{\bf Czech}\\ 
class & \#  & Decl. class & gender(s) & class & \#  & gender \\ \midrule
S1/P1    &     1157    &      Decl I 	& \textsc{msc}, \textsc{neut} & masculine, inanimate 2    &           823 & \textsc{msc}  \\
S3/P3    &    1105     &     Decl VI & \textsc{fem}  & feminine, \textit{-a}  &     818 & \textsc{fem}\\
%xS1/P2    &    542   &       Decl I & (m,n), phon. 
S1/P0    &     264    &      Singularia Tantum & \textsc{msc}, \textsc{neut}, \textsc{fem} & feminine, pl \textit{-e}   &   275 & \textsc{fem} \\
S1/P5    &     256    &      ``default \textit{-s} PL'' & \textsc{msc}, \textsc{neut}, \textsc{fem} &  neuter, \textit{-o} &  149 & \textsc{neut} \\
S3/P0    &    184     &     Singularia Tantum & \textsc{msc}, \textsc{neut}, \textsc{fem} & neuter, \textit{-en\'i}  &  133 & \textsc{neut} \\%, as per Alexiadou \& M\"uller\\
S1/P1u    &   154     &     Decl II & \textsc{msc} & masculine, animate 2, pl \textit{-i})  &  130 & \textsc{msc}\\
S2/P3     &    151      &    Decl V & \textsc{msc} & masculine, animate 1, pl \textit{-i})  &  112 & \textsc{msc}\\
S1/P3     &    70   &       Decl IV & \textsc{msc}, \textsc{neut}  & feminine, pl \textit{-i}    &   80 & \textsc{fem}\\
S3/loan   & 67 &  Loanwords & \textsc{msc}, \textsc{neut}, \textsc{fem} &  masculine, animate 1, pl \textit{-ov\'e}  &   55 & \textsc{msc}\\
S3/P1  &       11    &      Decl VIII & \textsc{fem}    & masculine, inanimate 1  &   32 & \textsc{msc} \\
S1/P4u    &    51   &       Decl III & \textsc{msc}, \textsc{neut}  & special, masculine, pl \textit{-ata}  &   26 & \textsc{msc}\\
%S3/P10    &    59    &      Loanwords & & 
S3/P5    &     49    &      ``default \textit{-s} PL'' & \textsc{msc}, \textsc{neut}, \textsc{fem} &  neuter, \textit{-e/-\u{e}/-\'i}    &   21 & \textsc{neut} \\%, as per Alexiadou \& M\"uller\\
%xS3/P2     &    52     &     Decl VIII & (f), phon. & 
S1/loan    &    41    &      Loanwords & \textsc{msc}, \textsc{neut} & masculine, animate 1, pl \textit{-\'e}  &   18 & \textsc{msc} \\
S3/P1u    &    35    &      Decl VII & \textsc{fem} & 	&		&	\\
S1/P4     &    25      &    Decl III %Speculation: P4 is P4U without an umlautable vowel. Only exception is "Verhalt", and I don't understand what they mean by that. (Sach-Verhalt is S1/P1)
& \textsc{msc}, \textsc{neut} &	&	&	\\
S1/P2u   &   24      &    Decl II & \textsc{msc}, phon. & 	&		&	\\
 \midrule
Total & 3684 & & & & & 2672 &\\ \bottomrule
    \end{tabular}
    %\end{adjustbox}
\end{center}
    \caption{Declension Classes.\ `class' refers to the declension class identifier. For German these came from CELEX2, for which `S' refers to a noun's singular form and `P' refers to its plural, and `Decl. class' refers to the classical conception of class from \textit{Brockhaus Wahrig W{\"o}rterbuch}--- `\#' refers to the number of tokens in the declension class, and `gender' refers to the gender(s) present in each class (if available).}
    \label{tab:NounClass}
\end{table*}

 \section{Further Notes on Preprocessing}\label{append:classes}

The final breakdown of our declension classes is given in \autoref{tab:NounClass}. After extracting declension classes from CELEX2, we made some additional preprocessing decisions, usually based on orthographic or other considerations. For example, we combined the classes S1 with S4 classes, P1 with P7, and P6 with P3 because the difference between each member of any of these pairs lies solely in spelling (a final $<$s$>$ is doubled in the spelling when GEN.SG \textit{-(e)s}, or the PL \textit{-(e)n} is attached). 


Whether a given singular, say S1, becomes inflected as P1 or P2---or, for that matter, the corresponding umlauted versions of these plural classes---is phonologically conditioned \citep{alexiadou2008}. If the stem ends in a trochee whose second syllable consists of schwa plus /n/, /l/, or /r/, the schwa is not realized, i.e., it gets P2, otherwise it gets P1. For this phonological reason, we also chose to collapse P1 and P2.

We also collapsed all loan classes (i.e., those with P8--P10) under one plural class `Loan'. This choice resulted in us merging loans with Greek plurals (like P9, \textit{Myth-os / \textbf{Myth-en}}) with those with Latin plurals (like P8, \textit{Maxim-um / \textbf{Maxim-a}} and P10, \textit{Trauma / \textbf{Trauma-ta}}). This choice might have unintended consequences on the results, as the orthography of Latin and Greek differ substantially from each other, as well as from the native German orthography, and might be affecting our measure of higher form-based MI for S1/Loan and S3/Loan classes in Table 3 of the main text. One could reasonably make a different choice, and instead remove these examples from consideration, as we did for classes with fewer than 20 lemmata. 


The preprocessing for Czech was a bit less involved, since the classes were derived from an edit-distance heuristic. A fluent speaker-linguist identified major noun classes by grouping together nouns with shared suffixes in the surface (orthographic) form. If the differences between two sets of suffixes in the surface form could then be accounted for by positing a basic phonological rule---for example, vowel shortening in monosyllabic words---then the two sets were collapsed into one set. 

Among masculine nouns, four large classes were identified that seemed to range from ``very animate'' to ``very inanimate.'' The morphological divisions between these classes were very systematic, but there was substantial overlap: dat.sg and loc.sg differentiated animate 1 from animate2, inanimate1 and inanimate2; acc.sg, nom.pl and voc.pl differentiated animate 2 from inanimate1 and inanimate2, and gen.sg differentiated inanimate1 from inanimate2 (see \autoref{fig:czechparad}. Further subdivisions were made within the two animate classes for the apparent idiosyncratic nominative plural suffix, and within the inanimate2 class, where nouns took either -u or -e as the genitive singular suffix. This division may have once reflected a final palatal on nouns taking -e in the genitive singular case, but this distinction has since been lost. All nouns in the inanimate 2 "soft" class end in coronal consonants, whereas nouns in the inanimate 1 "hard" class have a variety of final consonants.

Among feminine nouns, the feminine -a class contained all feminine words that ended in -a in the nominative singular form. (Note that there exist masculine nouns ending in -a, but these did not pattern with the feminine -a class). The feminine pl -e class contained feminine nouns ending in \textit{-e}, \textit{-\v{e}}, or a consonant, and as the name suggests, had the suffix  \textit{-e} in the nominative plural form. The feminine pl -i class contained feminine nouns ending in a consonant and had the suffix  \textit{-i} in the nominative plural form. No feminine nouns ended in a dorsal consonant. 

Among neuter nouns, all words ended in a vowel. 

\begin{figure}[ht]
    \centering
    \includegraphics[width=\columnwidth]{figs/CzechParadigm.png}
    \caption{Czech paradigm for masculine nouns.}
    \label{fig:czechparad}
\end{figure}


\section{Some prototypical examples}

To explore which examples, across classes might be most prototypical, we samples the top five highest and lowest suprisal examples. The results are in \autoref{tab:results5-meaning}. We observe that the lowest surprisal from form for each language generally come from one class:  feminine, \textit{-a} for Czech and S3/P3 for German. These two classes were among the largest, having lower class entropy, and contained feminine nouns. Forms with higher surprisal generally came from several smaller classes, were predominately masculine. This sample size is small however, so it remains to be investigated whether there is a statistically significant relationship between gender, class size, and surprisal.

\begin{table*}[h]
\begin{center}
\small
%\begin{adjustbox}{width=\pagewidth}
\begin{tabular}{lcclcc}
\toprule
 %\multicolumn{6}{c}{\bf Highest and Lowest Surprisal Examples by Form} \\ 
 \multicolumn{3}{c}{\bf Czech} & \multicolumn{3}{c}{\bf German} \\ 
  stem & class & $\Entr(class|form)$ & stem & class & $\Entr(class|form)$ \\
 \midrule
 \it azalka & feminine, \textit{-a} & $6.1 x 10^{-5}$ & \it Kalesche & \textsc{fem}, 6, S3P3 & 0.013 \\
 \it matamatika & feminine, \textit{-a} & $6.2 x 10^{-5}$ & \it Tabelle & \textsc{fem}, 6, S3P3 & 0.013 \\
 \it \v{c}tvrtka & feminine, \textit{-a} & $6.6 x 10^{-5}$ & \it Stelze & \textsc{fem}, 6, S3P3 & 0.014 \\
 \it paprika & feminine, \textit{-a} & $6.7 x 10^{-5}$ & \it Lende & \textsc{fem}, 6, S3P3 & 0.014 \\
 \it matoda & feminine, \textit{-a} & $6.7 x 10^{-5}$ & \it Gamasche & \textsc{fem}, 6, S3P3 & 0.015 \\ \hline
 \it ptakopysk & masculine, animate 1, pl \textit{-i} & 1.34 & \it Karton & \textsc{msc}, 1, S1P5 & 2.03 \\
 \it \v{s}pendl\'ik & masculine, inanimate 2 & 1.34 & \it Humus & \textsc{msc}, ?, S3P0 & 2.06 \\
 \it hospod\'a\v{r} & neuter, \textit{-en\'i}, derived from verb (instr-pl) & 1.36 & \it Mufti & \textsc{msc}, 1, S1P5 & 2.19 \\
 \it dudl\'ik & masculine, inanimate 2 & 1.39 & \it Magma & \textsc{neu}, ?, S1P10 & 2.23 \\ 
 \it z\'aznamn\'ik & masculine, inanimate 2 & 1.48 & \it Los & \textsc{neu}, 1, S1P1 & 2.43 \\
\bottomrule
\end{tabular}
%\end{adjustbox}
\end{center}
\caption{Five highest and lowest surprisal examples given form and meaning (w2v) by language.} \label{tab:results5-meaning}
\end{table*}


\clearpage