Learn Turkish: Kedi aniden bir bardak kırdı. - The cat suddenly broke a glass.

The verb root is kır- (to break). To make it past tense, we add a form of the -DI suffix. Since the vowel in kır- is an undotted 'ı', 4-way vowel harmony rules tell us to use -dı. We do not add an extra personal ending because the 3rd person singular ('he/she/it') takes no personal suffix in the past tense.

Why isn't there an object suffix on bardak? Doesn't 'glass' need the accusative case here?

We only use the accusative case for specific, definite objects ('the glass'). Because of the word bir (a/an), bardak is an indefinite object ('a glass'), so it stays in its plain, dictionary form. If the sentence were 'The cat broke the glass', we would add the accusative suffix and say bardağı kırdı.

Why does bir bardak come right before the verb?

In standard Turkish word order, indefinite objects like bir bardak are strongly attached to the verb and must be placed immediately before it. This is why the adverb aniden (suddenly) goes before the object, rather than between the object and the verb.