も

1. Origins, structure, and basic meaning

• Structure: Add も after an additional item to apply the same predicate to it.
• Basic usage: It adds another item to one already mentioned or understood from context.
  • 私もその映画を見たいです。 means the speaker wants to see that movie as another person does.

2. Common pitfalls and similar expressions

• What is being added
  • 私も映画を見る adds a viewer, while 私は映画も見る adds something viewed. The position of も changes the scope of the added information.
• Combining with other particles
  • It normally replaces が or を when adding a subject or object, but forms such as 学校にも行く and 家でも勉強する can retain に and で to mark their roles.
• Addition in negative sentences
  • 弟も行きません means the younger brother is not going, like another person. The following predicate determines whether the statement is affirmative or negative.