potuissent
potuissent is a Latin form of possum, meaning “be able, can”. It is the 3rd person plural pluperfect active subjunctive.
Found 92 times in the Latin texts on Socratos.
Where it is used
Caesar, De Bello Gallico 1.26.5: … enerunt, cum et propter vulnera militum et propter sepulturam occisorum nostri [triduum morati] eos sequi non potuissent.
All forms of possum (conjugation table)
Source: Socratos (socratos.org), a free reader for Ancient Greek and Latin. Grammar from the Perseus Treebank and Morpheus; dictionary entries from Lewis & Short, A Latin Dictionary (Perseus Digital Library, CC BY-SA). Counts are from the texts on Socratos.