Irregular verbs are verbs that don't follow the normal pattern used in giving tense to verbs (as is the case with regular verbs). Instead, they have their own individual ways of adding tense.
For instance, in English we would end most past tense verb usages with the letters ED ("work", "clean", and "thank" become "worked", "cleaned", and "thanked"). But with irregular verbs, we make much different changes to them ("see", "think", and "do", become "saw", "thought", and "did"). The Portuguese language has instances such as these, and we will explore them in this section.
There are several levels of irregularity in Portuguese verbs. Most irregular of all are the so-called anomalous verbs, which are only two: ser and ir. These two verbs present stem change within the Present Indicative tense, which means that not all persons begin the same way:
ser ir eu sou vou tu és vais você é vai ele/ela é vai nós somos vamos vós* sois ides vocês são vão eles/elas são vão
- Vós is considered archaic, and is hardly heard today in Brazil, yet is still used in Portugal
Furthermore, curiously, in several tenses (the Perfect and Plus-quam-perfect Preterites Indicative, the Imperfect and Future Subjunctive) the conjugation is exactly the same for these two verbs:
indicative subjunctive perfect plusquamperfect imperfect future eu fui fora fosse for tu foste foras fosses fores ele/ela foi fora fosse for nós fomos fôramos fôssemos formos vós fostes fôreis fôsseis fordes eles/elas foram foram fossem forem
There is also stem change in the Present Subjunctive, but the stems remain the same for all persons and numbers and they differ in each verb:
ser ir eu seja vá tu sejas vás ele/ela seja vá nós sejamos vamos vós sejais vades eles/elas sejam vão
The following are sections dedicated to the different tenses used for irregular verbs:
- Present tense irregular verbs
- Future tense irregular verbs
- Imperfect tense irregular verbs
- Preterite tense irregular verbs
Here is a list of the most common irregular verbs, along with their meanings (the links refer to the wiktionary project):
- ir - to go
- ser - to be (as in a state of being)
- estar - to be (as in location or temporary state)
- dar - to give
-zer/-der (so/ço-go) verbs
Only irregular in P.I.
- crer - to believe
- fugir - to run away
- odiar - to hate
- polir - to polish
- progredir - to proceed
- prover - to provide
- rir - to laugh
- subir - to climb
Only/mostly irregular in P.P.S.
Only irregular in first person P.I.
- dormir (eu durmo) - to sleep
- medir (eu meço) - to measure
- ouvir (eu ouço) - to hear
- pedir (eu peço) - to ask for
- perder (eu perco) - to lose/to miss
- seguir (eu sigo) - to follow
- valer (eu valho) - to be valid/to be worth
Only 1-2 exceptions
- haver - very irregular verb, auxiliar and sometimes with the meaning "to exist"