It is "had sung".
Present tense - singing Past participle - sung
Sang is the past tense of sing. The present perfect tense of sing is I/We/You/They had sung; He/She/It has sung.
I sang I have sung is the present perfect tense. You would not say, "I sung the song well."
sang, not sung. "I sang a song" is correct, but "I sung a song" is not. You would say "I have sung a song", which is present perfect tense.
Existed is the past tense. The past perfect tense is had existed.
The past perfect tense is had sung.
Present tense - singing Past participle - sung
Sang is the past tense of sing. The present perfect tense of sing is I/We/You/They had sung; He/She/It has sung.
I sang I have sung is the present perfect tense. You would not say, "I sung the song well."
sang, not sung. "I sang a song" is correct, but "I sung a song" is not. You would say "I have sung a song", which is present perfect tense.
Existed is the past tense. The past perfect tense is had existed.
Present Continuous: They are singing.Past Continuous: They were singing.Unless you want the past tense of the word "sing," in which case:Simple Past: They sang.Past Perfect: They had sung.
The past tense of "sing" would be "sang" or "sung".
The future tense of "sung" is "will have sung." In English, the future perfect tense is formed by using "will have" followed by the past participle form of the verb. So, in this case, "sung" is the past participle form of the verb "sing," and when combined with "will have," it creates the future perfect tense.
The past tense is bled, and the past perfect tense is had bled.
The past tense of sit is sat; the past perfect tense is had sat.
The future perfect tense of sing is "will have sung."