Common mistakes learners make with ことがある include:

1. Mixing up ことができる:

   • Many learners confuse ことがある (which talks about experiences) with ことができる (which talks about what someone can do). For example, saying "日本語を話すことがある" could mistakenly mean that someone is able to speak Japanese instead of saying they have experience speaking it.

2. Wrong grammar form:

   • Some learners use the basic form of a verb when they should use the past form. The right way to do it is "Verb (past tense) + ことがある." So instead of saying "行くことがある" (which is the basic form), you should say "行ったことがある," which means "I have been (there)."

3. Using it too broadly:

   • Learners sometimes use ことがある in situations where it doesn’t fit, like for things they do regularly. For example, saying "毎朝コーヒーを飲むことがある" makes it sound like drinking coffee every morning is something that happens sometimes, rather than an everyday habit.

To avoid these mistakes, students can:

• Practice the differences: Focus on understanding the differences between showing what you can do and what you have experienced by doing special exercises.

• Look at the context: Notice clues in sentences that help you choose the right form and meaning.

• Review regularly: Go over grammar rules often. Studies show that repeating things can help you remember them better, by up to 80%!