What is the subjunctive, and how is it used?

The subjunctive mood is used in Spanish, in contrast with the "normal" indicative mood, to signify possibility- as opposed to reality in the indicative. The mnemonic WEIRDO can be used to simplify the situations in which this mood is used, with the letters standing for Wishes, Emotions, Impersonality, Recommendations, Doubt, and Ojalá. A modification to the conjugation of the present tense indicative is also required- the 'O' is taken from the end of the present tense first person singular conjugation, and it is replaced with either -a, if the infinitive of the verb ends in -ER or -IR, or -e if it ends in -AR. Some verbs are irregular in this mood, but certainly fewer than in other conjugations. Many students struggle with the subjunctive due to it never being taught as such in English, but it can be simplified as above to allow for its use while the student gains confidence in the unfamiliar mood.