Infinitive after desde?

Question

In “ Cada domingo estudio español ________ almuerzo.”  since the subject is the same in both clauses, can’t you use the infinitive without que “desde terminar el” ?

Silvia Píriz · Accepted Answer

Hola Pat B.
Your reasoning about using the infinitive when the subject is the same is absolutely right in general, but here the key factor is the conjunction being used.
With “desde que”, Spanish requires a conjugated verb because it introduces a subordinate clause. That’s why the correct structure is Cada domingo estudio español desde que termino el almuerzo. Using an infinitive after desde in this context (desde terminar…) isn’t possible.
If you want to use an infinitive, you need a different structure, such as después de, which does allow it when the subject is the same: Cada domingo estudio español después de terminar el almuerzo.
So the difference comes down to the construction: desde que + conjugated verb vs después de + infinitive.
I hope this helps clarify things!
Saludos,Silvia