"To" as part of an infinitive - preposition?

[mommybunny]

DD (Y4) is learning prepositions, and while I know what they are, I'm struggling to explain them to her. She is in turn struggling to learn them. I've copied out some sentences from a favourite book of hers for her to identify where the prepositions are, but some have "to" used as part of an infinitive ("they manage to convince themselves"). Is the "to" a preposition used in that sense? If not, then does it just become part of the verb "to convince"? I've looked at some online videos about teaching prepositions and they all said the preposition must have an object, either a noun or pronoun, which is why I'm confused...

TIA.

www.khanacademy.org/humanities/grammar/partsofspeech#the-preposition

try this?

An infinitive verb, like to run, to read, to be and so on - the to in those isn't a preposition. Examples like to the bank, to me - that's using it as a preposition.

It helps me to remember the "position" part of preposition , but if that doesn't help you, ignore it.