gratias
gratias is a Latin form of gratia, meaning “favor, thanks; (abl.) for the sake of”. It is the accusative plural feminine noun.
Found 421 times in the Latin texts on Socratos.
Where it is used
Caesar, De Bello Gallico 1.41.2: princepsque X. legio per tribunos militum ei gratias egit quod de se optimum iudicium fecisset, seque esse ad bellum gerendum paratissimam confirmavit.
Pliny the Younger, Epistulae 6.3.1: Gratias ago, quod agellum quem nutrici meae donaveram colendum suscepisti. Erat, cum donarem, centum milium nummum; postea decrescente reditu etiam pretium minuit, quod nunc te curante reparabit.
Plautus, Asinaria 3.2.545: Perfídiae laudes grátiasque habémus merito mágnas,
All forms of gratia (declension 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.