In order to use the Present Subjunctive there must first be an element of doubt in the sentence.  You will recognize the words which should ring alarm bells for you to alert you to move to the Subjunctive.

In order to form the Present Subjunctive – go to the 1st person singular or the yo part of the verb e.g. Hablar – hablo.  Remove the o – habl and add the following endings.

Although this is called Present Subjunctive, in English this translates as will (future tense) or would (conditional tense).  There is no future Subjunctive.  If in English we hear will or would it is Present Subjunctive.

E.g.  i hope i will win the lottery.  Espero que gane la lotería

E.g. I wish that I would win the lottery. Espero que gane la lottería.

EXAMPLES

Ellos prefieren que hablemos español – They prefer that we speak Spanish.

Espero que ella estudie – I hope that she studies

Dudo que tengas dinero – I doubt that you have money

There are six irregular verbs in Present Subjunctive.

E.g. Espero que él esté allí – I hope that she will be there.

E.g. Dudo que ella sepa la respuesta. I doubt that she knows the answer.