Exercise : Singular Nouns ~ Subject or Object?
Subject Object      1. puer	Subject Object      2. Sextus	Subject Object      3. statua	Subject Object      4. puerum	Subject Object      5. piscina
Subject Object      6. hortus	Subject Object      7. fragorem	Subject Object      8. Corneliam	Subject Object      9. villa	Subject Object      10. Cornelia
Subject Object      11. hortum	Subject Object      12. Marcum	Subject Object      13. Marcus	Subject Object      14. Sextum	Subject Object      15. arbor
Subject Object      16. puellam	Subject Object      17. arborem	Subject Object      18. villam	Subject Object      19. vox	Subject Object      20. vocem
line 1 correct, screen turns this colour lines 1 & 2 correct, screen turns this colour lines 1, 2 & 3 correct, screen turns this colour if all answers are correct, the screen will turn this colour.

These are the different sorts of endings you have come across so far which show if a noun is a subject or an object.

SUBJECT	OBJECT
piscina	piscinam
vir	virum
servus	servum
fragor	fragorem