Learn Turkish: Her pazar yarışı izlerdik. - We used to watch the race every Sunday.

It combines the aorist (habitual) suffix and the past tense. The stem is izle- (to watch). We add -r for the aorist, then -di for the past tense, and finally -k for "we". Together, izlerdik means "we habitually watched" or "we used to watch".

Why is the aorist suffix just -r here in izlerdik, rather than -ar or -ir?

Because the verb stem izle- ends in a vowel. When a verb ends in a vowel, the aorist suffix is always just -r, making it izler-. You only use the -ar/-er or -ır/-ir/-ur/-ür forms for verbs ending in a consonant.

Why does yarış (race) have an -ı at the end in yarışı?

That is the definite accusative case. Because they watched "the" race (a specific, known race) rather than just "a race" or racing in general, the direct object yarış takes the accusative suffix -ı.

Why isn't the word for Sunday (pazar) capitalized here?

In Turkish, days of the week and months are only capitalized when they refer to a specific, exact date (like 25 Mayıs Pazar). When talking about days in general, like "every Sunday" (her pazar), they are written with a lowercase letter.