Learn Turkish: Bugün evde kaldım ve sıkıldım. - I stayed at home today and got bored.

Both verbs use the witnessed past tense suffix -dı followed by the first-person singular ("I") suffix -m. The root of "to stay" is kal-, which becomes kaldı (stayed), and then kaldım (I stayed). Similarly, sıkıl- (to get bored) becomes sıkıldım (I got bored).

Why is the "I" suffix just -m here? Shouldn't it be -um or -ım like in the present tense?

The past tense has its own special set of personal suffixes! In the present continuous tense, you use endings like -um or -im (for example, kalıyorum - I am staying). But for the direct past tense, the "I" suffix is just a single -m added directly to the past tense marker, creating endings like -dım, -dim, -dum, or -düm depending on vowel harmony.

Why does the sentence use evde instead of just ev?

Ev means "house" or "home". To say you stayed at home or in the house, you need to add the locative suffix -de (or -da), which means "in", "on", or "at". So, ev + de = evde (at home).