si

Everyday

1. (music) The seventh note of the do-re-mi scale in some countries, now usually called «ti» in English (do, re, mi, fa, so, la, ti). tree →
2. SI (science) — short for the International System of Units (from French «Système international»), the metric units scientists use, like metres, kilograms and seconds. tree →
3. (Spanish, Italian) «sí» means «yes» in Spanish and «si» means «if» or «yes» in other languages; it is not an English word. tree →
4. In pronunciation guides, si is a syllable written to show how to say part of a name, as in Scyros. tree →

In the lessons

In music lessons «si» may appear in older or foreign do-re-mi scales; in science lessons «SI units» are the standard units for measuring. In language lessons and on the street pupils may hear «¡Sí!» from Spanish speakers, sounding like English «see». Si is also a nickname, short for Simon (a name).

Examples

• In some countries they sing "do, re, mi, fa, sol, la, si." tree →
• In English we usually sing "ti" instead of "si". tree →
• The SI unit of length is the metre. tree →
• Write your answer in SI units: metres, kilograms or seconds. tree →
• "¿Quieres pizza?" "¡Sí!" — that means "Yes!" in Spanish. tree →
• Si, short for Simon, is in my football team. tree →

Note

«si» alone is not an everyday English word. «SI» is written in capitals for the units. Spanish «sí» (yes) has an accent; Spanish «si» without the accent means «if». In maths and science «SI units» means metres (m), kilograms (kg), seconds (s), amperes (A), kelvin (K), moles (mol), candelas (cd).