 
In written French the more usual option is the inversion (as we do in English as well). 
| Examples |  | 
| Ils lisent des livres. 
                                          => Lisent - 
                                          ils des livres? |  | 
| They read books. => Do they read books? (Read they books?) |  | 
Pronouns that are attached to the verb in these sentences, are connected to them with a hyphen. 
There is 
one important rule to be taken into account: Only pronouns can be attached this way to a verb, nouns need another construction.