"Ik spreek je."
Translation:I will talk to you.
It's present tense in Dutch, but the meaning is that one expects to talk in the future. For this kind of construction it doesn't really work to use present tense in English, hence future tense is used.
No, "tegen" is a preposition that when put after "spreken", means "towards".
Ask your fellow dutch people if you don't believe. That is one of the things that I have learned at my dutch courses.
It is more detailed here (sorry, it is in french): http://www.nlfacile.com/prepositions-fixes-neerlandais_2_24444.htm