Impersonal Class 9 Statements

In Swahili, the Class 9 subject prefix i- functions as a true expletive or "dummy" subject, mirroring the English "it" specifically in abstract framing clauses like "it is necessary" or "it seems."

1. Framing Clauses
In verbs like inawezekana (it is possible), inabidi (it is necessary), or inasemekana (it is said), i- does not refer to any hidden noun; it syntactically frames the entire following clause as the subject. These verbs are commonly used across tenses, such as in the past (ilibidi = it was necessary) and future (itabidi = it will be necessary).

2. Phonological Gliding
The prefix attaches directly to the tense/aspect marker. When it attaches to a vowel-initial tense marker—most notably the gnomic/habitual -a- tense—the i- glides to y-. For example:

• i- + -a- + bidi → yabidi (it is necessary)
• i- + -a- + faa → yafaa (it is suitable)

3. Following Verbs: Subjunctive or Infinitive
When using impersonal framing verbs of obligation or necessity (such as inabidi or yafaa), or impersonal phrases with adjectives (like ni muhimu), the following verb is typically in the Subjunctive -e if there is a specific subject (e.g., inabidi uende = it is necessary that you go). If the statement is general and applies to no one in particular, you can use the Infinitive ku- (e.g., inabidi kwenda = it is necessary to go). However, Swahili also allows specifying the subject by attaching an object prefix directly to the framing verb. When doing this, you can follow it with either the infinitive or the subjunctive (e.g., inanibidi kwenda or inanibidi niende = it is necessary for me to go).

4. Object Infixes and Negation
Verbs like -bidi and -faa frequently take object infixes to show who is obligated or suited (e.g., inanibidi, inambidi, yakufaa). To negate these impersonal constructions, use the negative Class 9 prefix hai-. For example, inawezekana becomes haiwezekani (it is impossible), inabidi becomes haibidi (it is not necessary), and inafaa becomes haifai (it is not suitable). Note that -bidi is an Arabic loanword ending in -i, which is why its final vowel does not change to -i in the negative, unlike standard Bantu verbs such as -faa. While haibidi is grammatically correct, conversational Swahili often prefers phrases like sio lazima (it is not a must) or hakuna haja (there is no need). Furthermore, to express negative obligation (e.g., "you must not go"), you negate the following subjunctive verb instead of the framing verb (e.g., inabidi usiende = it is necessary that you do not go).

5. Contrasts to Watch Out For
Swahili divides the English dummy "it" between i- (for abstract concepts and clauses) and ku- (for environment and atmosphere, like kuzuri or kumekucha). Do not confuse the impersonal i- with the locative/existential ku-. Use There Is or Are for "there is" (e.g., kuna shida = there is a problem) or for environmental conditions (e.g., kuna baridi = it is cold). Furthermore, for impersonal statements using adjectives (like "it is important"), use the Present Copula ni in the present tense. When using ni (is), Swahili drops the dummy subject entirely; you do not say i muhimu or ina muhimu, you just say ni muhimu. However, in the past and future tenses, you must use the i- prefix attached to -kuwa (e.g., ilikuwa muhimu = it was important, itakuwa muhimu = it will be important).