Siempre te digo mis secretos. I always tell you my secrets. (I always tell my secrets to you.)
El doctor les da la medicina. The doctor gives them the medicine. (The doctor gives the medicine to them.)
Before a conjugated verbAttached to an infinitive Te quiero ver ◦ I want to see you. Le va a hablar. ◦ She is going to talk to him. Quiero verte. ◦ I want to see you. Va a hablarle. ◦ She is going to talk to him.
Write the IOP first, then the DOP. Te lo doy. I give it to you.
If le/les comes before lo, la, los, las then it changes to “se.” El camarero se lo sirvió. The waiter served it to him.