Questions & Answers about Sen teneffüste bütün elmaları yemişsin.
Why is it yemişsin instead of yedin?
yemişsin uses the -miş past tense (the evidential or hearsay past). You use this when you didn't see the action happen yourself, but you figured it out later (for example, by seeing an empty apple bowl) or heard it from someone else. The English translation shows this with the word "Apparently".
Why does teneffüs get the ending -te instead of -de?
The ending means "at" or "in" (the locative case). Normally this is -de or -da. But because teneffüs ends in a hard/voiceless consonant (s), the d in the suffix changes to a t to match it. You might know this as the "Fıstıkçı Şahap" consonant mutation rule.
Why is it elmaları and not just elmalar?
The -ı at the end of elmaları is the accusative case marker. We use it because the apples are a specific direct object in this sentence. The word bütün (all) makes it clear we are talking about a specific, known group of apples, so we need the ending to show you ate "the" apples.
Could I use hepsi instead of bütün to say "all the apples"?