[Grammar] Help me correct these sentences

[nicci]

im having problems identifying problems in these 3 sentences:

1.A good teacher is nice and kind. The teacher treats students kindly and is always very nice.
2. The idea of the teacher was exciting for all the students.

Can some please help me identifying the problems with explanations

Thank you

 

[tedtmc]

A good teacher is nice and kind. The teacher treats students kindly and is always very nice.

The second sentence is a repeat of what the first sentence says.

The idea of the teacher was exciting for all the students.

Shouldn't that be 'to'?

not a teacher