"I recognize this boy and this car."
Translation:Tohoto chlapce a tento automobil poznávám.
Both auto and automobil are accepted. Automobil is masculine, so it would need tento. Auto, however is neuter, so it would need toto. Also, chlapce requires tohoto. Adding -to or -hle to the end of the demonstrative turns "the/that" into "this." See earlier comments above.
chlapce is genitive or accusative of chlapec. See https://forum.duolingo.com/comment/27749621/So-many-different-ways-of-saying-things-hoch-kluk-chlapec