It's the same with any native speakers of any language, I'm sure. I don't know why I say/type half the stuff I do in English, it just SEEMS right to me.

The subjunctive tense in Spanish = when you're saying "Quiero una novia quien juegue videojuegos" (someone who may not exist) as opposed to using "juega" in a sentence like "Mi novia juegan los videojuegos" (someone who you know exists) and you use it in a few other instances... something like that XD; It's hard to know when to use it!