REPLACE field3 with ALLTRIM(Field1)+" "+alltrim(field2) ALL

>I have a table made in a weird way
>
> The guy built 2 small fields
>
> eg.
> Field 1: "I am afraid"
> Field 2: "of ghosts"
>
> How can I make a fusion of this 2 fields in one new field
> and keep a space of a digit between the frases
>
>"I am afraid of ghosts"
>
> The table has over 10,000 records
>
> Moises