The full form of this verb phrase is:
it has been decided -- this is a passive present perfectverb eg
It has been decided to go ahead with the sports day in spite of the rain
It's been decided to go ahead with the sports day in spite of the rain
The infinitive would be "to decide", the present tense would be "decide(s)", and the past tense IS "decided". The word decided is the past tense. The present and future tense are (PRESENT) decides or decide and (FUTURE) will decide.
The present perfect tense of decide is:I/You/We/They have decided.He/She/It has decided.
The past tense of decide is decided.
Decided and reached are past tense.
I think you mean "decide", which is "decided" in the past tense.
Yes.
decided
use it in a sentance i have decided...... verb
"Has been decided" is the correct form. For example, "The matter has been decided."
Decided
The future tense of "have been" is "will have been."
Decisive is not a verb so it does not have a past tense form. Decisive is an adjective