Esperanto's personal pronouns are easy. Before we get to them, let's consider some of them in other languages.
Just how do you say "you" in Spanish? The answer is that it depends on how many people you are addressing and how familiar you are with them. Your choices are
tú,
usted,
vosotros,
ustedes, or
vos.
Vosotros is not used in all Spanish-speaking countries and
vos is used even less. This can cause much confusion for non-native speakers.
French makes things a little easier. There are only
tu and
vous. Even with only two choices, it is easy to make mistakes.
Vous can be both plural and singular but formal.
Tu is always singular and always informal. Do I use tu with my lover, my pets, my children, my best friend? Again, the answer is "It depends." If you incorrectly use
tu you may likely offend someone.
Italian can also be confusing. Italian also has an informal word,
tu. The formal word is
Lei.
Lei can also mean "she". Supposedly this is easy enough to figure out in context, due to Italian's complex system of verb endings. But do you really want to go to that much trouble?
Esperanto has a simple answer -
vi (pronounced "vee").
Vi is used as singular you and plural you. You can confidently use
vi with everyone you meet. Address a head of state as
vi and you're not going to unintentionally offend anyone.
Esperanto does have another word for you, but ci (pronounced "tsee") is used the same way we use "thou" in English. That is,
ci is used when praying or in poetry, but never in conversation.
Here are the personal pronouns in Esperanto:
Mi - I
Vi - You
Li - He
Ŝi - She
Ĝi - It
Oni - "One" or "they" or "people"
Ni - We
Ili - They
Pretty simple.
Oni is the odd one out. This is used similarly to the French
on. In sentences where "they" is not specific,
oni is used.
"Our neighbors are evil. They killed our cat." - We would use
ili in this case because "they" refers to the neighbors. In Esperanto:
Niaj najbaroj estas malbonaj. Ili mortigis nian katon.
"They say cats have nine lives." - We would use
oni here because "they" does not refer to someone specific. In Esperanto:
Oni diras ke katoj havas naŭ vivojn.