Learn Turkish: Ağaçtaki kuş bize bakabilir. - The bird on the tree might look at us.

The suffix combination -(y)abil followed by the aorist tense (like -ir here) expresses both physical ability ("can") and probability ("might/could"). In everyday Turkish, this form is the standard way to say "might". Context tells you which meaning is intended, and here, a bird "might" look at us makes perfect sense.

Why do we need the -ki in ağaçtaki? Wouldn't ağaçta be enough?

Ağaçta just means "in/on the tree" as a general location. By adding -ki, you turn that location into an adjective that links directly to the noun next to it. So, ağaçtaki kuş specifically means "the bird that is on the tree".

Why does the sentence use bize instead of bizi for "us"?

The verb bakmak (to look) always requires the dative case (the direction suffix -a or -e). In English you look at something, but in Turkish you look to something. So biz (we) takes -e and becomes bize.

Why is it ağaçta rather than ağaçda before the -ki suffix?