Simple Past & Present Perfect

Simple Past vs. Present Perfect

When do we use the simple past, and when do we use the present perfect?

Simple Past

We use the simple past to talk about actions that happened and were completed within a finished time period.

Examples:

• Tom bought a new computer yesterday.
• Jan wrote her essay last week.
• They passed the TOEFL test last month.
• I went to New York last year.
• She turned in her assignment two days ago.

Note: The time expressions (yesterday, last week, two days ago) all refer to a specific, completed period in the past.

Present Perfect

We use the present perfect to describe actions completed in the past when the time period is not yet finished (such as this week, this month, this year, or in my life). Often, we do not use a specific time expression at all because the focus is on how the completed action relates to the present, rather than exactly when it happened.

Examples:

• Tom has bought a new computer, so he can complete his assignment.
• Jan has written her essay, so she doesn’t have to study tonight.
• They have passed the TOEFL test, so they can begin university courses.
• I have been to New York several times, so I know the city pretty well.
• Because she has turned in her assignment, she doesn’t have to come to class today.

Present Perfect vs. Present Perfect Progressive

We also use the present perfect or the present perfect progressive to talk about actions that started in the past and continue into the present. In these cases, we typically use for (to indicate a length of time) or since (to indicate a specific starting point in time).

Examples:

• I have lived in New York for three years. OR I have been living in New York since I came to America.
• Akiko has studied English for one year. OR She has been studying English since last year.
• He has been traveling for three days. OR He has traveled since Monday.

Key Revisions Made:

• Fixed a sentence fragment in the Present Perfect section (“Such as this week…”).
• Clarified the wording around time expressions in the Present Perfect section for better pedagogical flow.
• Tweaked the “Akiko” example in the final section to actively demonstrate the use of since, rather than repeating for.
• Added bolding and blockquotes to make the grammatical targets stand out visually.

---

Exercise

Fill in the blank with either the simple past or the present perfect form of the verb in parentheses.

1. I ________ (drink) three glasses of water so far today.
2. In 2024, the company ________ (launch) a new line of smartwatches.
3. Oh no, I ________ (lose) my house keys, and now I am locked out!
4. He ________ (work) at the bakery for six months, and he loves it there.
5. We ________ (eat) dinner at that incredible Italian restaurant last Friday.

Answer Key

1. have drunk Present Perfect: “Today” is an unfinished time period.
2. launched Simple Past: “In 2024” refers to a specific, completed time period in the past.
3. have lost Present Perfect: There is no specific time expression; the stress is on the completed past action causing a present result (being locked out right now).
4. has worked (or has been working) Present Perfect / Present Perfect Progressive: “For six months” indicates an action that started in the past and is not yet finished.
5. ate Simple Past: “Last Friday” refers to a finished time period in the past.