Idem facit Caesar equitatumque omnem ( ) praemittit, qui videant, quas in partes hostes iter faciant. (BG 1,15)
In this sentence
omnem agrees with 'equitatum' as singular but as a subject of 'videant' 'equitatum' is plural. How should I understand this?
Grammar books say that 'nomen mihi est Marcus.' is 'My name is Mark.'. Then, Did Romans never say like 'meum nomen est Marcus.' and it is wrong?
In “Idem facit Caesar equitatumque omnem .......praemittit, qui videant, quas in partes hostes iter faciant” (Caesar, De Bello Gallico, book 1,chapter 15) there is a “concordatio ad sensum”, i.e. a grammatical connection according to sense where agreement or reference is determined by sense, and then the verb “videant” in the relative/purpose clause “qui videant” is in the plural as it refers to the collective noun “equitatus”(the cavarly) which is composed of many individuals, of course.
So, “equitatumque omnem .......praemittit, qui videant...” means:”Caesar sends ahead all the cavalry, to see.. (literally, “who should see...”)”.
As for “My name is Mark”, Latin says “Mihi nomen est Marcus” (where the name is put in the nominative agreed with “nomen”) or “Mihi nomen est Marco” (where the name is put in the dative agreed with “mihi”).
In fact, with "nomen est" and similar expressions, the name is often put in the Dative as a kind of apposition with the person, though the Nominative is also common.
But the Romans never said “Meum nomen est Marcus” as it was wrong.