Learn Turkish: Tahtayı yontmak için aleti şöyle kullanmak lazım. - It is necessary to use the tool like this to whittle the board.

While both can translate to "like this," şöyle is specifically used when you are about to physically demonstrate an action or direct someone's attention to exactly how something is done. By saying şöyle kullanmak lazım, the speaker is likely picking up the tool to show the listener the correct technique right at that moment.

Why do both "tahta" (board) and "alet" (tool) have accusative endings here?

They are the specific direct objects of two different verbs in the sentence. Tahtayı (the board) receives the action of yontmak (to whittle), and aleti (the tool) receives the action of kullanmak (to use). Because we are talking about a specific board and a specific tool, they both require the accusative case ending.

What does the structure "-mak için" mean in "yontmak için"?

When you place için (for) immediately after a verb in its full dictionary form (-mak or -mek), it creates the meaning of "in order to." Therefore, yontmak için directly translates to "in order to whittle."

Can I use "gerekiyor" instead of "lazım" at the end of this sentence?

Yes, you absolutely can! Kullanmak gerekiyor means the exact same thing as kullanmak lazım. Both are very common and natural ways to express that performing a certain action is necessary.