Spanish question

Hi, what is the difference between these two sentences?

1. Los extraterrestres les vendieron un motor que les permitiría viajar a velocidades superiores a la de la luz.

2. Los extraterrestres les vendieron un motor que les permitiera viajar a velocidades superiores a la de la luz.

Gracias por la ayuda.

1 uses the conditional, les permitiria = would permit/allow them...

2 uses the past subjunctive, les permitiera = permited/allowed them (in the subjunctive)

I think you would just use the present or past tense, permite or permitio'.

I'm not a grammar teacher, so if this is wrong please correct me.

Both sentences have exactly the same meaning.

Good question forastero.
I can see 3 differences in meaning:

1. In the end,the engine allowed them to go faster than light
2. We don't know whether the engine can go faster than light or not.
3. Los extraterrestres les vendieron un motor que les permitió viajar a velocidades superiores a la de la luz. ==> The engine allowed them to go faster than light.

The main difference is that the first one is a well-formed Spanish sentence, whereas the latter doesn't make any sense. You outh to have said:

Los extraterrestres querían venderles un motor que les permitiera viajar a velocidades superiores a la de la luz.

Cheers.