Why does my Spanish teacher do this?
At school my Spanish teacher always misses out the 'yo' when she teaches us to sa 'I do/eat/drink/am ...... ' etc.<pre>
Anybody know why?</pre>
Because you can do this in Spanish, each verb has a conjugation (i,e a different word for each person yo, tú, él, etc), so if you use the personal pronoun and the conjugated verd together, it could be emphatic or redundant.
In all languages, whenever you say something that you didn't have to say, the listener assumes that you meant something special by it. I think the flavor of "Yo lo bebo" is something like the English "I will drink it" where you raise your voice when you say "I." That is, it sounds like you thought the listener was expecting someone else to drink it.
If that's not the impression you meant to give (and it almost never is), then it's wrong to say "yo". Your teacher is doing the right thing.
Yikes! It's because I started with a future example, then decided he might not have learned the future yet, but then I fogot to edit the English to match.
Sorry about that!
Because using subject pronouns when not needed for clarity or emphasis is often seen as a beginner's mistake.
In Costa Rica, where I started learning Spanish by immersion, I heard "yo" so infrequently that I literally didn't know how to pronounce it! It was only on Duolingo that heard it often enough to learn how to say it. So I can attest that native Spanish speakers omit it more often than not.