現在完成時可以用來表示發生在過去某一時刻的,持續到現在的情況,常與for,since連用. Mary has been ill for three days. I have lived here since 1998. 現在完成時往往同表示不確定的過去時間狀語連用,如already, yet, just, before, recently, lately等: He has already obtained a scholarship. I haven"t seen much of him recently (lately). We have seen that film before. Have they found the missing child yet 現在完成時常常與表示頻度的時間狀語連用,如often, sometimes, ever, never, twice, on several occasion等: Have you ever been to Beijing I have never heard Bunny say anything against her. I have used this pen only three times. It is still good. George has met that gentleman on several occasions. 現在完成時還往往可以同包括現在時間在內的時間狀語連用,如now, up to these few days/weeks/months/years, this morning/week/month/year, now, just, today, up to present, so far等: Peter has written six papers so far. Man has now learned to release energy from the nucleus of the atom. There has bee too much rain in San Francisco this year. The friendly relations and cooperation between our two countries have been enhanced in the past few years. Up to the present everything has been successful. 現在完成時表示現在之前業已完成的動作,雖然其效果或影響仍然存在但已不再繼續,但是有一些現在完成時的句子,在後面加上for+一段時間,則現在完成時的動作就表示延續性. Thomas has studied Russian. (現在不再學俄語) Thomas has studied Russian for three years. (=Thomas began to study Russian three years ago, and is still studying it now.(同第2點用法第一個例句) 現在完成時還可以用來表示過去的一個時間到現在這段時間內重複發生的動作. We have had four texts this semester. =================== 現在完成時的“完成用法”和“未完成用法” 1.現在完成時的"完成用法" 現在完成時的"完成用法"指的是動作發生在過去某一時刻並已結束，但該動作對現在產生了影響，與現在情況具有因果關係。 例如：He has turned off the light.他已把燈關了。(動作結束於過去，但說明的是現在的情況--燈現在不亮了。) 現在完成時"完成用法"的特點是動作不延續，因此，該時態只能與表示不定的過去時間狀語(如：already，yet，before，recently等)、頻度時間狀語(如：never，ever，once等)、包括現在時刻在內的時間狀語(如：this morning ／ month ／year...，today等)連用。 例如： Have you found your pen yet？你已找到你的鋼筆了嗎？
2.現在完成時的"未完成用法"
現在完成時的"未完成用法"指的是動作開始於過去某一時刻，一直延續到現在，或可能還要繼續下去。
例如：He has lived here since 1978.自從1978年以來，他一直住在這兒。(動作起始於1978年，一直住到現在，可能還要繼續住下去。)
I have been in the army for more than 5 years.我在部隊已經呆了五年多了。(動作開始於5年前，一直延續至今，有可能還要繼續下去。)
此種用法的句中常需一個表示一段時間的狀語(由since或for引導)，或表示與現在時刻相連的時間狀語(如：up to now，so far)等。
例如：I have heard nothing from him up to now.到目前為止我沒有他的任何訊息。
have(has)+過去分詞
1.現在完成時用來表示現在之前已發生活或完成的動作或狀態,但其結果卻和現在有聯絡,也就是說,動作或狀態發生在過去但它的影響現在還存在.
I have lost my wallet.(含義是:現在我沒有錢花了.)
Jane has laid the table.(含義是:已可以吃飯了.)
Michael has been ill.(含義是:現在仍然很虛弱)
He has returned from abroad. (含義是:現在已在此地)
現在完成時可以用來表示發生在過去某一時刻的,持續到現在的情況,常與for,since連用. Mary has been ill for three days. I have lived here since 1998. 現在完成時往往同表示不確定的過去時間狀語連用,如already, yet, just, before, recently, lately等: He has already obtained a scholarship. I haven"t seen much of him recently (lately). We have seen that film before. Have they found the missing child yet 現在完成時常常與表示頻度的時間狀語連用,如often, sometimes, ever, never, twice, on several occasion等: Have you ever been to Beijing I have never heard Bunny say anything against her. I have used this pen only three times. It is still good. George has met that gentleman on several occasions. 現在完成時還往往可以同包括現在時間在內的時間狀語連用,如now, up to these few days/weeks/months/years, this morning/week/month/year, now, just, today, up to present, so far等: Peter has written six papers so far. Man has now learned to release energy from the nucleus of the atom. There has bee too much rain in San Francisco this year. The friendly relations and cooperation between our two countries have been enhanced in the past few years. Up to the present everything has been successful. 現在完成時表示現在之前業已完成的動作,雖然其效果或影響仍然存在但已不再繼續,但是有一些現在完成時的句子,在後面加上for+一段時間,則現在完成時的動作就表示延續性. Thomas has studied Russian. (現在不再學俄語) Thomas has studied Russian for three years. (=Thomas began to study Russian three years ago, and is still studying it now.(同第2點用法第一個例句) 現在完成時還可以用來表示過去的一個時間到現在這段時間內重複發生的動作. We have had four texts this semester. =================== 現在完成時的“完成用法”和“未完成用法” 1.現在完成時的"完成用法" 現在完成時的"完成用法"指的是動作發生在過去某一時刻並已結束，但該動作對現在產生了影響，與現在情況具有因果關係。 例如：He has turned off the light.他已把燈關了。(動作結束於過去，但說明的是現在的情況--燈現在不亮了。) 現在完成時"完成用法"的特點是動作不延續，因此，該時態只能與表示不定的過去時間狀語(如：already，yet，before，recently等)、頻度時間狀語(如：never，ever，once等)、包括現在時刻在內的時間狀語(如：this morning ／ month ／year...，today等)連用。 例如： Have you found your pen yet？你已找到你的鋼筆了嗎？2.現在完成時的"未完成用法"
現在完成時的"未完成用法"指的是動作開始於過去某一時刻，一直延續到現在，或可能還要繼續下去。
例如：He has lived here since 1978.自從1978年以來，他一直住在這兒。(動作起始於1978年，一直住到現在，可能還要繼續住下去。)
I have been in the army for more than 5 years.我在部隊已經呆了五年多了。(動作開始於5年前，一直延續至今，有可能還要繼續下去。)
此種用法的句中常需一個表示一段時間的狀語(由since或for引導)，或表示與現在時刻相連的時間狀語(如：up to now，so far)等。
例如：I have heard nothing from him up to now.到目前為止我沒有他的任何訊息。
注意：(1)現在完成時的未完成用法只適用於延續性動詞，不可用於終止性動詞，即瞬間完成或延續時間很短的動詞。如：come，go，arrive，leave，join，become，die等。
(2)現在完成時常見兩種句型：
①主語＋have / has been＋for短語
②It is＋一段時間＋ since從句
例如：He has been in the League for three years.或It is three years since he joined the League. 他入團已三年了。
：英語教科書與輔導報