Whats the difference between preterit, imperfect, and subjunctive?
Im having a hard time conjucating... words in the preterit, imperfect, and subjunctive form. So can you please tell me the difference between the three?
4 Answers
Preterite tense is past tense, for example, I was sick...Estuve enferma(irregular).
Imperfect tense is used when you use to do something or past continuous tense, for example, I used to sing alot...Yo cantaba mucho, or I was singing ....Cantaba.
The Subjuctive is used when you wish, hope, suggest, recommend something for someone else, for example, I hope you come ......Espero que vengas..
Wow that's a pretty big question for your very first one here on SD lol - so firstly, welcome to the forum. I'll just start with a simple answer. There's more than it to this but hopefully it'll give you a basic idea 
The preterite is one of the past tenses. It refers to actions which were completed at the time in the past to which you refer.
He said hello. (Él) Dijo hola. (Dijo - decir in the preterite (third person sing)
The action was over at the time you are talking about.
The imperfect past tense is used to refer to action that was still going on at the time that you were speaking about.
I was eating an apple while I watched the movie.
Yo estaba comiendo una manzana mientras veía la película.
In the moment you are referring to the eating and the watching of the movie were still in progress, the imperfect tenses there (estaba & veía) help you to express that.
The subjunctive is a whole 'nother story as they say, not a tense this one is a mood which has many and varied uses, including expressing the wish of one person that another do the action etc. If I were you I'd concentrate on the preterite and imperfect first
To start, what is normally termed the preterit and imperfect are referring to simple (not compound) past tenses of the indicative mood. The subjunctive mood has past tenses of its own.
I want to share this link just to see if I can. I hope it works, but sorry if it doesn't
Yes, it works. Now you can read about the tenses to your heart's content.
