No, you can't. You must use present subjunctive (or present perfect subjunctive).

The reason (in Spanish) is because if you say that "Marta vendrá a la fiesta", you really mean it, and then it doesn't make sense that you hope something you declare that it is going to happen. The same applies to the conditional.

Okay. I thought as much but.......It's good to know for sure.

Thank you Lazarus

No, cond. and fut belong to the indicative mode (mood). Is does not matter that the English word will or shall appears in the English version, it is still in the subj mode.

látigo said:

No, cond. and fut belong to the indicative mode (mood). Is does not matter that the English word will or shall appears in the English version, it is still in the subj mode.

Thanks látigo

I don't think we can use the conditional even in English here. "I hope that Marta would come to the party..." doesn't sound right to me. Can you think of a situation where you would say that?

As for the future tense, you can imply that with context. "Espero que Marta venga a la fiesta mañana" has to be "I hope Marta will come to the party tomorrow."

This little trick with indicative/subjunctive might help, patch:

If you hear the end of a sentence, and someone says...

... María vendrá a la fiesta.

since it is an indicative tense, you can safely assume that someone thinks or suspects that María is coming to the party; this is being purposefully stated in order to share this belief, suspicion, or knowledge. Now, when you say "I hope she is coming to the party", no one is purposefully stating that she is coming. Therefore, being indicative, the beginning of that sentence could have been:

Sé que...
Sospecho que...
Me han dicho que...

All compatible with the idea of presenting or declaring the information of "María coming to the party" as a belief, a suspicion... On the other hand, if you hear:

... María venga a la fiesta.

you cannot assume that the speaker, or anyone else believes such thing, because in subjunctive you don't declare things. The beginning of the sentence must be something where the speaker does not want to declare that she is coming, or simply can't do it. The beginning of this sentence could have been:

Espero que...
Dudo que...
No creo que...

James Santiago said:

"I hope that Marta would come to the party..." doesn't sound right to me. Can you think of a situation where you would say that?
This is, simply, not English. You could say "I hoped that ... ". In this case there would be some doubt about whether she did, in fact, come to the party (although the usual assumption would be that she didn't, absent further qualification).

James Santiago said:

I don't think we can use the conditional even in English here. "I hope that Marta would come to the party..." doesn't sound right to me. Can you think of a situation where you would say that'As for the future tense, you can imply that with context. "Espero que Marta venga a la fiesta mañana" has to be "I hope Marta will come to the party tomorrow."

No I can't either, James. It was a bad example. For some reason I had it in my mind that...

"conditional" and "future" = "not indicative."

...but now I know better.

Thanks

lazarus1907 said:

This little trick with indicative/subjunctive might help, patch:If you hear the end of a sentence, and someone says...... María vendrá a la fiesta.since it is an indicative tense, you can safely assume that someone thinks or suspects that María is coming to the party; this is being purposefully stated in order to share this belief, suspicion, or knowledge. Now, when you say "I hope she is coming to the party", no one is purposefully stating that she is coming. Therefore, being indicative, the beginning of that sentence could have been:Sé que...Sospecho que...Me han dicho que...All compatible with the idea of presenting or declaring the information of "María coming to the party" as a belief, a suspicion... On the other hand, if you hear:... María venga a la fiesta.you cannot assume that the speaker, or anyone else believes such thing, because in subjunctive you don't declare things. The beginning of the sentence must be something where the speaker does not want to declare that she is coming, or simply can't do it. The beginning of this sentence could have been:Espero que...Dudo que...No creo que...

I think I'll save this text for further reference!!! Thanks again.