Complex sentence: Pulau Tekong is the largest island of Singapore's smaller islands (aside from the main island of Singapore), and is found off Singapore's northeastern coast, but is actually nearer to Johor, Malaysia than the main island of Singapore itself.
Split into simpler sentences: Pulau Tekong is the largest island of Singapore's outlying islands (aside from the main island). It is found off Singapore's northeastern coast, but is actually nearer to Johor, Malaysia than the main island of Singapore itself.