The indicative mood (sometimes referred to as the 'declarative mood', 'evidential mood', 'common mood',' or 'fact mood' ) is the one you're most likely to use. It states facts. Most sentences; statements and questions use the indicative mood.
England is green.
Why is England green?
Because it rains a lot in England.
!Note - Some linguists like to talk about the 'interrogative mood' for questions.