〜たり〜たりする

1. Origins, structure, and basic meaning

• Structure: Add り to a verb’s た-form to make its たり-form, and end a basic list with する.
  • 読む → 読んだ → 読んだり
  • 聞く → 聞いた → 聞いたり
• Basic usage: It lists a few representative actions from among several possibilities.
  • The listed actions are not necessarily an exhaustive account of everything someone does.

2. Common pitfalls and similar expressions

• Sentence tense
  • The earlier た-forms do not by themselves determine the tense of the whole sentence.
  • 〜たりします can describe habitual activities, while 〜たりしました can describe past activities.
• Exclusive choice
  • The construction does not mean that exactly one of the listed alternatives must be chosen.
  • Someone may do both actions, and other unlisted actions may also be involved.
• Order of actions
  • The order of the list does not establish the order in which the actions happen.
  • This differs from 〜てから or an expression meaning ‘then,’ which can make sequence explicit.
• A single たり
  • A sentence may give just one representative example with 〜たりする, so たり does not always have to appear twice.