Do you understand the necessity of this project?

The filesystem of my computer has broken down.

He is an expert in systems engineering.

That information is unnecessary.

That information is completely unnecessary.

Geographic Information Systems are very useful tools for map making and spatial data analysis.

The automotive navigation system in my car has downloaded the latest map data.

He was born as an illegitimate child and experienced many difficulties.

My grandfather used to till his privately-owned rice field.

Using the private railway makes commuting very convenient.