He always helps me when I'm in trouble.

Whenever he is feeling down, I always help him.

It's difficult to understand his explanation.

We should always remember the power of Kannon in difficult times.

His explanation was impossible to understand.

This ancient proverb, 'know the other side and yourself, and you will not be in danger in a hundred battles', teaches us the importance of understanding ourselves and others.

Natural language understanding is an important field of artificial intelligence.