Time expressions with Past Simple: when exactly did it happen?

Yesterday means the previous calendar day. Yesterday morning, yesterday afternoon and yesterday evening specify a part of that day. Last night often refers to the previous night or evening.

Last week, last month and last year mean the week, month and year before the current one. Last Monday refers to the previous Monday. In these expressions' usual meaning, do not put on/in/at or the before last: We met last week.

This rule applies specifically to those time expressions. In the last week can mean during the seven days up to now, while in the last week of June means during June's final week. These are different constructions, not errors simply because they contain in or the.

Two hours ago measures two hours backwards from the moment someone speaks. Name the length of time first, then add ago: a minute ago, three days ago, a year ago. For an approximate distance, say about a month ago or a long time ago.

Yesterday names a day, while one day ago expresses a distance in time. They refer to the same day in many conversations, but are not equally precise: yesterday could have been a few hours or more than twenty-four hours ago. If exact timing matters, specify a time and date; do not combine them into yesterday ago.

When the reference point is another event rather than now, before is often needed: two days before the trip. This is a brief boundary note: the lesson practises ago measured from speaking time, not every way of narrating from a past reference point.

Use in for a calendar year: in 2018. For the year to be past in a particular account, it must precede that account's speaking time. The named date does not change from day to day, unlike yesterday or last year.

Sometimes an exact date is unnecessary: when I was a child, when we were students, when she was younger. The when-clause establishes a clear past frame. Within it, you can name a single event or an action that was habitual then; there is no need to invent a birth year or personal details.

A time expression often comes at the end of a sentence. It can also come first to establish the frame: Last year, we changed our plans. This does not change the event's date. If an exercise asks for a particular position, that is a learning constraint, not a ban on other natural positions in English.

The time phrase remains in negatives and questions. After did/didn't, an ordinary verb takes the base form: Did you arrive yesterday? When used with be requires was/were, not did be. The short question When did it happen? helps you find out a time you do not yet know.

Yesterday and last night are compatible with more than Past Simple. Past Continuous, for example, presents an action in progress at a particular past moment. First establish what the speaker describes: a past fact, an ongoing action or another time relationship. The main target here is a past fact with a suitable time expression.

Today and this morning are not automatically present or past markers. At 18:00, the morning is over, so a completed morning event can be described in Past Simple. Even while the day continues, an individual event can be presented as a past fact: I paid at nine today. A summary up to now may take a different perspective. Do not choose the tense from today alone.

For your own message, make three decisions: what happened, when it happened and whether the listener needs that time detail. Do not repeat a marker in every sentence when the frame is already clear.