Before we begin, let's distinguish between the two types of do.
First, there's do the content word. This means it's a very verb-y verb. It means something along the lines of "to execute" or "to perform." It's the verb that means hacer in Spanish. Here are some sentences with this type of do:
- I did my homework last night.
- Do something!
- Bobby did the macarena.
- I'm not sure what to do.
Odds are, you're pretty familiar with this type of do already.
Next, we have the dummy verb do, which is what this section's all about. Dummy do is our guest of honor here. Let's get everyone acquainted.
There's no Spanish equivalent of dummy do...in most cases. This means that wherever do shows up as a dummy verb, Spanish ELLs tend to leave it out. Yep, we've been listening to you.
Dummy do pops up wherever the main verb of a sentence is all alone and needs some extra support. It's okay, you don't have to understand why a verb would ever need support. Linguists don't really understand either.
These are the situations where "do-support" happens:
- Yes/No Questions
- Negation
- Verb Phrase Ellipsis
- Emphasis
ELLs, pay attention to these situations. Be aware that you need to put do there. If you need review on any of these, read on.
1. Yes/No Questions
This is outlined in the Yes/No Question section of the Question Formation part of this module. It's also discussed in the "Do" Insertion section of our Verbs module, where we mainly cover semantic differences. Yeah, we talk about do a lot.
For a really brief review, here are the yes/no questions you might say...
- You know how to dance?
- She likes coffee?
- They went to the party?
Versus how you should say them...
- Do you know how to dance?
- Does she like coffee?
- Did they go to the party?
Bottom line: don't forget do in questions.
2. Negation
You probably learned this faster because knowing how to negate sentences is pretty important. What we're saying is, you've probably had a lot of practice with not.
Just for the record, insert do whenever you want to negate a sentence using not and there's no helping verb or modal verb. By the way, negating a sentence just means putting not before the main verb.
Here are some examples of sentences that would need do's help in order to be negated:
- I know her.
- My mom likes broccoli.
- Jonathan drinks coffee.
- You need another phone.
And here are those sentences with negation and do:
- I don't know her.
- My mom doesn't like broccoli.
- Jonathan doesn't drink coffee.
- You don't need another phone.
Depending on how you started learning English and when, you probably already know all this. Like other verbs, make sure you conjugate do in the third person singular.
3. Verb Phrase Ellipsis
Syntactic ellipsis is a fancy name for when you don't pronounce part of a sentence that's repeated or implied. The same thing exists in Spanish, but you don't use dummy do because—you guessed it—Spanish doesn't have that dummy.
Verb Phrase Ellipsis means you delete the main verb and usually anything after it—but only if the stuff you delete has a matching antecedent. If the sentence has a modal verb (can, will, should, could, would, etc.) and/or a helping verb (have, be), they stay where they are and you don't insert do.
Dummy do only comes to the rescue when the main verb is all by itself. This is because if you delete the main verb in Verb Phrase Ellipsis (VPE) when there's no modal or helping verb, that would mean the sentence doesn't have tense...which would be pretty weird.
Here are some examples of VPE where do comes to the rescue:
- Bobby doesn't like shrimp, but Tasha does [likes shrimp].
- Cat sneezes the same way I do [sneeze].
- Liz has a car, but I don't [have a car].
Notice how the stuff that gets replaced by do (in brackets) is pretty much the same as something that was said only a little bit earlier. Now imagine how weird, repetitive, and unnecessary it would sound if you said the stuff in brackets instead of do.
It would probably take you forever to talk about stuff.
4. Emphasis
Spanish uses sí in affirmative (or non-negative) sentences for emphasis. It's basically when you want to say, "Yes, what I'm saying is true." That might sound pretty confusing, so here are some Spanish examples of that:
- Sí tengo dinero.
- Carlos sí tiene novia.
- A Chava sí le gusta el mambo.
- Sí limpié mi cuarto.
In English, you use do instead of sí:
- I do have money.
- Carlos does have a girlfriend.
- Chava does like mambo.
- I did clean my room.
This isn't true in all contexts, so don't directly translate sentences with affirmative sí.