Asked in Earth SciencesSpeleologyPeriodic Table
How has phosphorus been used in the past?
Asked in Energy, Wind Power
Has wind energy been used successfully in the past?
Asked in Waste and Recycling, Energy
Has biomass energy source been successfully used in the past?
Asked in The Difference Between
What is the different between the have and have been?
Asked in Conditions and Diseases
What is it called when phosphorus is used in the treatment of blood disorders?
Asked in Social Sciences
Has hydro energy been used successfully in the past?
Asked in Verbs
Where to use have been has been had been?
Have been and has been are both forms of present perfect. Use have been for I and plural subjects eg I have been to China. They have been to China. The doctors have been to China. Use has been for he/she/it and singular subjects eg he has been to China. The boy has been to China. Present perfect is used to talk about something that happened in the past but has result now or is important now Had been is past perfect the same form is used for all subjects eg He has been to China. We had been to China The doctor had been to China. Past perfect is usually used to talk about something that happened in the past before another thing that happened in the past (past simple). eg He had been to China when I last saw him. - saw = past simple
Asked in Elements and Compounds
What is the colour of the phosphorus allotrope in matches?
Asked in Example Sentences, Past Tenses
When do you use had in a sentence?