Between the ages of 2 and 3, your little chatter-box is likely to go through a big expansion in their vocabulary!
Your toddler will start to get pronouns and call themselves I or me, and you'll begin to get a few broken sentences. If your little one announces "Me jump big" don't tell them they're incorrect, instead repeat what they said modelling the correct grammar, while celebrating their achievement - "Yes, you jumped so high!! You are so clever!"
If by about 30 months (2 and a half years) your baby isn't talking at all, it might be worth a trip to the paediatrician. They may just be biding their time, but early intervention from a speech therapist is so important if there is anything underlying.