If it rains, the picnic will be cancelled

Indicative and counterfactual[edit]
See also: Counterfactual conditional and Indicative conditional
One of the most discussed distinctions among conditionals is that between indicative and counterfactual conditionals:
Indicative: If it is raining in New York, then Mary is at home.
Counterfactual: If it was raining in New York, then Mary would be at home.
These examples differ in both form and meaning. The indicative example uses the present tense form "is" in both its antecedent and consequent, while the counterfactual example uses the past tense form "was" in the antecedent and the modal "would" in the consequent.^[2] The counterfactual example conveys that the speaker thinks it isn't raining in New York, while the indicative example suggests that the speaker is agnostic about that possibility.
Linguists and philosophers of language sometimes avoid the term counterfactuals because not all examples express counterfactual meanings. For instance, the "Anderson Case" has the characteristic grammatical form of a counterfactual conditional, but does not convey that its antecedent is false or unlikely.^[3][4]
Anderson Case: If the patient had taken arsenic, he would have blue spots.^[5]
The term subjunctive has been used as a replacement, though it is also acknowledged as a misnomer. Many languages do not have a subjunctive (e.g., Danish and Dutch) and many that do have it don’t use it for this sort of conditional (e.g., French, Swahili, all Indo-Aryan languages that have a subjunctive). Moreover, languages that do use the subjunctive for such conditionals only do so if they have a specific past subjunctive form. ^[6][7][8]
Recently the term X-Marked has been used as a replacement, with indicative conditionals renamed as O-Marked conditionals.^[9][10][11]