## 系词 *esse*、动词 *posse*

<table>
<thead>
<tr><th>esse</th><th colspan=3>单数</th><th colspan=3>复数</th></tr>
<tr><th>主动态直陈式</th><th>一</th><th>二</th><th>三</th><th>一</th><th>二</th><th>三</th></tr></thead>
<tbody>
<tr><th>现在时</td><td>sum</td><td>es</td><td>est</td><td>sumus</td><td>estis</td><td>sunt</td></tr>
<tr><th>未完成时</td><td>eram</td><td>erās</td><td>erat</td><td>erāmus</td><td>erātis</td><td>erant</td></tr>
<tr><th>将来时</td><td>erō</td><td>eris, ere</td><td>erit</td><td>erimus</td><td>eritis</td><td>erunt</td></tr>
<tr><th>完成时</td><td>fuī</td><td>fuistī</td><td>fuit</td><td>fuimus</td><td>fuistis</td><td>fuērunt, fuēre</td></tr>
<tr><th>过去完成时</td><td>fueram</td><td>fuerās</td><td>fuerat</td><td>fuerāmus</td><td>fuerātis</td><td>fuerant</td></tr>
<tr><th>将来完成时</td><td>fuerō</td><td>fueris</td><td>fuerit</td><td>fuerimus</td><td>fueritis</td><td>fuerint</td></tr>
</tbody>
</table>

<table>
<thead>
<tr><th>posse</th><th colspan=3>单数</th><th colspan=3>复数</th></tr>
<tr><th>主动态直陈式</th><th>一</th><th>二</th><th>三</th><th>一</th><th>二</th><th>三</th></tr></thead>
<tbody>
<tr><th>现在时</td><td>possum</td><td>potes</td><td>potest</td><td>possumus</td><td>potestis</td><td>possunt</td></tr>
<tr><th>未完成时</td><td>poteram</td><td>poterās</td><td>poterat</td><td>poterāmus</td><td>poterātis</td><td>poterant</td></tr>
<tr><th>将来时</td><td>poterō</td><td>poteris, <br>potere</td><td>poterit</td><td>poterimus</td><td>poteritis</td><td>poterunt</td></tr>
<tr><th>完成时</td><td>potuī</td><td>potuistī</td><td>potuit</td><td>potuimus</td><td>potuistis</td><td>potuērunt, <br>potuēre</td></tr>
<tr><th>过去完成时</td><td>potueram</td><td>potuerās</td><td>potuerat</td><td>potuerāmus</td><td>potuerātis</td><td>potuerant</td></tr>
<tr><th>将来完成时</td><td>potuerō</td><td>potueris</td><td>potuerit</td><td>potuerimus</td><td>potueritis</td><td>potuerint</td></tr>
</tbody>
</table>

前接 *potis* 的词干 *pot-*，经历 -ts- &rarr; -ss-、-tf- &rarr; -t-、-tess- &rarr; -ss- 的规律变化