It is not easy to 'teach' a 2 year old boy because he likes to jump and run to here and there. We have to know the secret. The secret is, that's how they learn.
Sometimes, we mothers, especially for a full time working mom like me, we can't wait to see the result. As our child learns something, we want him to understand and remember it forever.
Children born with zero skill, zero knowledge, zero problem... So they are free to absorb everything around them. So, no matter how active our children are, they are actually absorbing.
My boy is a very active ones. He won't stay put a second even during 'study time', except watching his favourite videos. What I do just let him play while I am teaching him. Usually he'll respond while playing. So it will be play and learn sessions.
To teach our children need lots of love and patient.