In English language there are six infinitives with transitive verbs and four with intransitive.
Infinitive forms of a transitive verb
Active | Passive | |
---|---|---|
Pres. simple | to form | to be formed |
Pres. progressive | to be forming | / |
Perfect simple | to have formed | to have been formed |
Perf. progressive | to have been forming | / |
Infinitive forms of an intransitive verb
Active | Passive | |
---|---|---|
Pres. simple | to sit | / |
Pres. progressive | to be sitting | / |
Perfect simple | to have sit | / |
Perf. progressive | to have been sitting | / |
An infinitive may be used with or without the particle to.
An infinitive without to is known as the bare or plain infinitive
To is pronounce /tu/ before an infinitive beginning with a vowel, but /tə/ before and infinitive beginning with a consonant.