BE ABLE TO と CANの違い。高上 英語 似た表現比較⑤

be able to と CANの違い。よく英語の軽い動画で紹介されているが体系的にきちんと学んだことのある人は少ないのではないだろうか? 実際そのような動画で紹介されているよりも奥が深く、こうしてCHATGPTに聞いてみると、より深く勉強することができた。


Please tell me about the difference between the words “be able to” and “can” with specific examples.


“Be able to” and “can” both express ability, but they are used in slightly different ways and can have nuanced differences in certain contexts. Here are the primary distinctions between the two:

  1. Tense Variations:
    • “Can” is modal and doesn’t change to indicate different tenses. If you want to express ability in the past or future, you would generally use “be able to.”
      • Past: I was able to finish the task yesterday. (You wouldn’t typically say “I could finish the task yesterday.”)
      • Future: I will be able to attend the meeting tomorrow. (You can’t say “I will can attend the meeting tomorrow.”)
    • However, “could” can be used as a past tense form of “can” in certain contexts:
      • When I was younger, I could run a mile in six minutes.
  2. Situational vs. General Ability:
    • “Can” is often used to express a general ability, whereas “be able to” might be more situational.
      • I can swim. (General ability)
      • I was able to swim to the shore when my boat capsized. (Specific situation)
  3. Formal vs. Informal Contexts:
    • “Be able to” can sometimes sound more formal or less direct than “can.”
      • Formal: I am able to provide the information you need.
      • Informal: I can give you that info.
  4. When Other Modals are Present:
    • If you have another modal verb (like “might” or “should”), you usually can’t use “can” right after it and would use “be able to” instead.
      • Incorrect: I might can come to the party.
      • Correct: I might be able to come to the party.
  5. Infinitive Forms:
    • Since “can” doesn’t have an infinitive form, “be able to” is used in such structures.
      • I want to be able to speak French fluently.
  6. Emphasis:
    • Sometimes, “be able to” can add more emphasis or importance to the statement, particularly when talking about a specific achievement or overcoming a challenge.
      • Despite all the challenges, we were able to complete the project on time.

It’s essential to note that in many cases, both “can” and “be able to” are interchangeable without much difference in meaning. For example:

  • I can help you with that.
  • I am able to help you with that.

Both sentences are correct and convey a similar message, but the choice between them might be based on formality, rhythm, or personal preference.





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