When is verb following "soler" conjugated?

Question

All the examples use an infinitive after "soler," but in the first test question, the verb following "soler" is conjugated. How do we know when to conjugate the verb after a conjugated "soler?"

Accepted Answer

Hola William
Soler is always followed by an infinitive, never a conjugated verb.
I checked all the sentences in this lesson and there is no conjugated verb at all. 
I think you may have got confused with this one that looks similar to a conjugated verb, but it isn't:
Rodrigo y yo solemos levantarnos a las ocho de la mañana.
Levantarnos is still an infinitive, but we use the verb levantar(se) as reflexive, so that extra bit at the end "nos" is simply the reflexive pronoun that you need to add to the infinitive. 
Other examples could be:

Yo suelo ducharme temprano.
I usually have a shower early.
Andrés suele afeitarse por la mañana.
Andrés usually shaves in the morning.

All reflexive verbs.
I hope it clarified it.