In LLPSI Cap. X the infinitives are introduced, for example: "Iulius Marcum non videre, sed audire potest". Which I would translate as "Iulius can't see marcus, but can hear him". So in this case, "audire" and "videre" would be "to hear", "to see".
So far so good... But in the grammar part of the chapter, another example of the use of infinitive is mentioned: "Pater Filium vocare audit, et acurrere videt" - Which I would translate as "The father hears the son calling, and sees him running".
In this case, is it still Infinitive? Shouldn't it be more like the "-ing" suffix (thanks, Grochojad... ) in english? After all, until now I've seen "the son runs" phrased as "filius curr-it-", so I'm having so troubles reading "Pater Filium vocare audit, et acurrere videt" as "The father hears the son calls, and sees him runs".
I guess it's not straightforward for me because I'm used to other non-latin languages, so I would really appreciate if anyone could shed some light on this.