"I eat the tomato, drink the tea."
Translation:Ben domatesi yerim, çayı içerim.
The root word is "domates" so the suffix you see there is just -i for accusative since there is no vowel ending, not -si like you would use for possessive after a vowel.
I eat the tomato. = Domatesi yiyorum. (domates-i)
I eat the meatball. = Köfteyi yiyorum. (köfte-yi)
BUT, for third person possessive (his/her/its) you add -(s)I(n). Use the "s" if there is a vowel before it. Use the "n" if there is a case ending after it.
His tomato = domatesi (domates-i)
I eat his tomato. = Domatesini yiyorum. (domates-in-i)
His meatball = köftesi (köfte-si)
I eat his meatball. = Köftesini yiyorum. (köfte-sin-i)
For the sake of Duo, yeah, but it's actually not as hard and fast as its taught here. The tenses don't overlap with English very well and it depends in large part on how you're taught. FWIW my mental picture of the aorist/geniş zaman fits much more with an unclear potential action "would" or "may," not a definite action like is implied with the present simple.
well "tomato" in the nominative in Turkish is "domates", there is a consonant. The consonants that change at the end of an accusative word are p, k, t and ç. You add "yi" if the word (in nominative) ends with the vowels e or i. The word does not (in the nominative) end with those vowels or a consonant that changes so you just add the "i" to "domates" because the last vowel in the word was an "e"