Pronouns
Two parallel sets — independent for the subject, attached for the object and possessor — distinguishing more persons than English does.
Arabic has more pronouns than English. It distinguishes masculine from feminine in the second and third person, has separate forms for two people, and has separate plural forms for groups of women. It also has two parallel sets: an independent set used for subjects and emphasis, and an attached set — suffixes — used to mark direct objects on verbs and possessors on nouns. The two sets carry the same person/gender/number information but never substitute for each other.
The independent pronouns
These are the pronouns you use as standalone subjects, in equational sentences, or for emphasis. In a verbal sentence the verb itself encodes person and gender, so an independent pronoun is often optional — much like Spanish or Italian.
The attached pronouns
This second set attaches to the end of a noun, verb, or preposition. On a noun it marks the possessor ("my book"); on a verb it marks the direct object ("he saw me"); on a preposition it is the object of the preposition ("with him").
How they attach in practice
A noun with an attached pronoun cannot also take al-. The possessor makes it definite already. So "my book" is kitaabii, never al-kitaabii.
Why English speakers struggle
Three points of friction. First, the gendered you: anta for a man, anti for a woman, with corresponding -ka versus -ki. English collapses these. You have to think about who you are addressing and gender the pronoun accordingly. Second, the dual: a separate form for "you two" or "they two" with no English equivalent — though the dual pronouns are heard less in dialect. Third, the rule that the attached pronoun is suffixed, so you must produce it together with the host word, not as a separate word.
Dialect notes
Spoken dialects simplify in predictable ways. Most lose the feminine plurals — antunna and hunna — collapsing into the masculine. The dual personal pronouns survive in some Gulf and rural dialects but are rare in everyday Egyptian or Levantine. Egyptian uses inta/inti for anta/anti, huwwa/hiyya for huwa/hiya, and intu and humma for the plurals. Levantine uses hayda/haydi for "this" and similar small phonetic shifts. The system is the same; the surface forms shift slightly.
What it's called in the Arabic tradition
A pronoun is ضَمير (Damiir). The independent pronouns are الضَّمائِر المُنْفَصِلَة (aD-Damaa'ir al-munfaSila), and the attached suffixes are الضَّمائِر المُتَّصِلَة (aD-Damaa'ir al-muttaSila). The classical grammarians arrange them in a fixed order: first person, second person, third person — and the order matters for some morphological rules.