Some verbs are usually followed by prepositions before the object of the verb. these are called dependent prepositions and they are followed by a noun or a gerund (‘ing’ form).
For is the dependent preposition for ‘wait’
We can use other prepositions with ‘wait’ – e.g. He waited at the bus stop – but ‘for’ is the dependent preposition.
Here are some other verbs with their dependent prepositions.
Verbs with ‘for’
With ‘from’
With ‘in’
With ‘of’
With ‘on’
With ‘to’
With ‘with’