Learn Turkish: Araba sürerken direksiyonu iki elle tutman lazım. - While driving, you must hold the steering wheel with two hands.

It means "while driving." It combines the verb root sür- (drive), the aorist tense ending -er (used for general habits or facts), and the suffix -ken (while). Adding -ken to the aorist form of a verb is the most common way to say "while doing something" in general.

Why is it iki elle instead of the plural iki ellerle for "two hands"?

In Turkish, nouns following a number or a quantity word always stay in their singular form. So, "two hands" is simply iki el. The -le at the end is the suffix meaning "with" (short for the word ile).

Why does direksiyon (steering wheel) have an -u at the end?

The -u in direksiyonu is the specific accusative case ending. It marks the steering wheel as the specific direct object of the verb tutmak (to hold). You are holding the specific steering wheel of the car you are driving.

How does the grammar in tutman lazım work to mean "you must hold"?