The imperfect subjunctive is formed by adding the following endings to the stem.
For all verbs this is formed from the third person plural preterite stem plus the set endings in the table below for the type of verb
What is meant by the 'stem' in this case is what is left after taking the 'ram' ending from the 'eles' form of the preterite tense.
Trying this with a regular verb (1st person singular form): FALAR > falaram - ram = fala > fala + sse = FALASSE
Trying this with an irregular verb (1st person singular form): FAZER > fizeram - ram = fize > fize + sse = FIZESSE
For the 'nós' and 'vós' forms, accents must be added as per the table below:
|...I was speaking
|...you were speaking
|...he was speaking
(also ela, você)
|...we were speaking
|...you (p) were speak||Vós fal
|...they were speaking
(also elas, vocês)