Translation:I don't want to go if you do not come with me.
I think this is difficult for those who have not studied the subjunctive. In this instance "for" is the future subjunctive of 'ir' and basically means 'will go' but the future subjunctive for 'ser' is exactly the same. I believe (if I remember correctly) the use of the subjunctive is caused by the word 'if ' 'se'. I agree that DL is making this very difficult for many people. The other problem is that for many of the exercises they are only presenting the second part of a complete sentence. Example: If I don't arrive at the station by 10 the train will have left. The future perfect expresses one future action that takes place before another future action. It may require a lot of head scratching for some of us.
really what is the point introducing all these tenses together. at the level we are now (which is still beginner) we need 3-4 tenses to keep things simple. it only confuses me. i live in Portugal and in every day conversations (in my case still limited) i don't need that advanced grammar.
I've only heard the tu form once conjugated with the tu form, usually recifenses and potiguares use the voce verb and the tu as pronoun. I think i've heard preachers say vos only when reading scripture. Basically un-necessary and a confusing crutch for english speakers with spanish experience.
"Will" is not used in subordinate clauses in 1st conditional sentences.
I don't want to go if you can't come with me.
"Will" is used after "if" in non-conditional sentences:
I don't know if I will go. (a statement of fact - not conditional)
Practical English Usage - Michael Swan (Oxford U Press)
The rule applies to the first conditional, a hypothesis about the present/future.
The explanation is here: https://www.perfect-english-grammar.com/first-conditional.html
emeyr, I think where you are getting confused is the difference between the different meanings of "will". In English there is "will" which designates the future tense. There is also "will" which stems from Old English and means "want to", which is perfectly acceptable when it follows "if".
Eu não quero ir se você não venir (vier?) comigo. Not to be picky, the English sentence does say "if you do not come with me." It would sound strange to say, "if you do not go with me." I'm going, and you're coming with me. But in Portuguese does it sound better to say, "I'm going, and you're going with me?"
Portuguese uses "ir" while "come" is used in English to express the same action.
We’re going for a drink. Would you like to come?
A gente vai sair pra tomar um drinque? Quer ir com a gente?