Learn Turkish: Bu maden çok tehlikeli, daha derin kazmamalıyız. - This mine is very dangerous, we must not dig deeper.

Let's break it down: kaz- (dig) + -ma (negative "not") + -malı (obligation "must/should") + -y- (buffer letter) + -ız ("we"). Notice that the negative suffix always attaches directly to the verb root, coming before the obligation suffix.

Why do we need the buffer letter -y- in kazmamalıyız?

The obligation suffix here ends in a vowel (-malı), and the "we" personal ending starts with a vowel (-ız). Because Turkish generally doesn't allow two vowels to sit right next to each other, we use -y- as a bridge to connect them.

How does daha derin mean "deeper"?

Turkish doesn't change the ends of words to mean "-er" like English does with "deep" and "deeper". Instead, you just put daha (more) in front of the adjective. So, daha derin literally translates to "more deep".

What is the suffix -li doing at the end of tehlikeli?

It turns a noun into an adjective. Tehlike means "danger" (a noun). Adding -li (which roughly means "with" or "containing") turns it into tehlikeli, meaning "dangerous".