| Form | si + present, then the present | Si quieres, puedes venir. | If you want, you can come. |
| Use | what usually happens when the condition holds | Si como mucho, me duele el estómago. | If I eat a lot, I get a stomach ache. |
| Comma | a comma follows the si clause when it comes first | Si llueve, no salgo. / No salgo si llueve. | If it rains, I don't go out. / I don't go out if it rains. |
| Spelling | si means if, sí with an accent means yes | Si quieres, vamos. / Sí, claro. | If you want, let's go. / Yes, of course. |
| B1Form | si + present, then the future | Si tengo tiempo, iré. | If I have time, I'll go. |
| B1Form | si + present, then the imperative | Si puedes, ayúdame. | If you can, help me. |
| B1Trap | never the future after si in a condition | Si viene Carlota, iremos al cine. | If Carlota comes, we'll go to the cinema. |