What are some examples of improper words?

When we speak and write articles, we should choose proper words and pay special attention to distinguish the subtle differences between some synonyms, otherwise we will make the mistake of using inappropriate words. For example:

Our classroom is wide and bright.

Xiao Ming doesn't investigate and discuss with others. His decisive action was criticized by everyone.

Xie Ming was absent from school for three days because of illness. He asked the teacher to help him review his lessons.

There is a couplet hanging on his wall.

The above four sentences are all poorly used. The word "extensive" is not used properly. Both "wide" and "spacious" have the meaning of large area and wide range, but "wide" is wider than "spacious" and is generally collocated with words such as Yuan Ye and land, while "spacious" is generally collocated with words such as room, auditorium and courtyard. This sentence means that the classroom is relatively large and should be described as "spacious". The original sentence does not distinguish the size range of synonyms. The word "decisive" in Example 2 is not used properly. "Decisiveness" is a commendatory term, which describes "doing or speaking" resolutely without hesitation. Example 2 means that Xiao Ming is arbitrary and critical, which is also a misnomer. The word "begging" in Example 3 is not used properly. "Begging" means "begging for food", which is too heavy for teachers to make up lessons. It is appropriate to use "request" here. This sentence does not distinguish synonyms, and it is also a misnomer. "One picture" in Example 4 is not appropriate. Because couplets have upper and lower couplets, we can only say "one pair" but not "one picture".