This is so, since Lizza Doolittle is the daughter of Alfred Doolittle in the play called "Pygmalion." In This work His central plot is developed around Eliza Doolittle, a street florist from the London underworld whose vulgar language arouses the interest of a phonetics professor named Henry Higgins.
The preposition 'since' always shows a time relationship from the past to the present. When you say 'since Monday' it means that he didn't have a car available from Monday until now.So, a time relatioship