Learn Turkish: Sen yoğurdu şekerle yersin. - You eat the yogurt with sugar.

This is an example of consonant softening. When a Turkish word ends in a hard consonant like -t and you add a suffix starting with a vowel, the -t usually softens to a -d to make pronunciation smoother. Here, adding the vowel -u changes yoğurt to yoğurdu.

Why is the accusative ending -u added to yoğurdu?

The accusative case is used to mark a specific direct object. Because the translation is "You eat the yogurt" rather than just "You eat yogurt" in general, you must add the accusative suffix -u to show that we are talking about a specific, known yogurt.

How does şekerle mean "with sugar"?

The suffix -la or -le is the attached, shortened version of the word ile, which means "with" in Turkish. Because the last vowel in şeker is an e, it follows vowel harmony and takes -le, making the word şekerle.

Why does the sentence use yersin instead of yiyorsun?

Yersin is in the aorist tense, also known as the simple present tense (geniş zaman). It is used to state habits, general facts, or typical behaviors (like how you usually eat your yogurt). If the person were eating the yogurt right this second, you would use the present continuous tense yiyorsun instead.