БичлэгComparative past simple and present perfect for 9th graders
Present perfect and simple past compared
The present perfect tense links the past and the present. It can be contrasted with the past simple tense.
The past simple tense | The present perfect tense |
The past simple tense may describe completed activities and past situations | The present perfect tense may describe activities or situations which began in the past and are still continuing |
| In 1976, 60% of families were couples with children. In 1981, 34% of children aged 20-24 lived with their parents. | The number of one person households has grown. Over the past twenty years, the average size of households has fallen. |
The past simple may describe activities without linking them to the present | The present perfect may describe completed activities whose impact is felt in the present |
| They completed the research in 1972. They arrived yesterday. | They have completed the research. (meaning: a short time ago; here it is). They have arrived. (meaning: a short time ago; here they are). |
With past simple verbs, the time may be specified | With present perfect verbs, indefinite time expressions may be used |
| They completed the research in 1972. They arrived yesterday. The number of one person households grew last year. | They have just completed the research. They have already arrived. The number of one person households has grown recently. |
