sisi

1. Emphasis and Contrast
Swahili is a pro-drop language. This means the verb itself tells you who is doing the action. For example, tunakwenda already means "we are going." Adding sisi makes it emphatic: Sisi tunakwenda means "WE are going."

2. We and Us
Unlike English, which switches between "we" and "us," the standalone word sisi can mean both. However, if "us" is the direct object of a verb, you cannot just put sisi after the verb. You must use the -tu- object marker inside the verb (e.g., wanatuona - "they see us"). You can add sisi for emphasis: wanatuona sisi ("they see US").

3. Possession (Our)
To say "our," you do not use sisi. Instead, Swahili uses the possessive root -etu, which changes its prefix to match the noun it describes (e.g., mtoto wetu - "our child").

4. Fusions
When combined with the conjunction na (and/with), it often fuses to become nasi (and us / with us).

5. Inclusive vs. Exclusive
Some languages have different words for "we (including you)" and "we (excluding you)." Swahili does not; sisi covers both meanings perfectly.

6. Common Phrases and Forms
Here are a few important related forms to become confident with:
• Sisi sote means "all of us" (using the root -ote). You will also frequently hear sisi wote in colloquial speech, but sisi sote is the strictly correct Standard Swahili form required in formal contexts. To say "both of us," speakers use sisi wawili or sote wawili.
• Sisi kwa sisi is a common idiom meaning "among ourselves" or "between us."
• Sisi wenyewe means "we ourselves" or "by ourselves" (using the root -enyewe).
• Kwetu means "our home" or "our place" (combining a locative prefix with the possessive -etu).
• Ni sisi or sisi ndio are the natural, everyday ways to say "it is us." Conversely, to say "it is not us," use si sisi. Because the negative copula si and the pronoun sisi look and sound similar, this is a famous phonetic stumbling block for beginners that you should pay close attention to!