9.2.1 unregular verbs in pretérito perfeito simples, difference poder <=> saber and estar <=> ser
In any little bit bigger bookshop one can buy for a cup of coffee very thin books that contain all the conjugations of all verbs. Of course you can buy these thin books as well from Amazon, but this is not recommended, at least if you don't want to life in a desert with no shops at all. The question is why they are so thin? The answer is simple. Inside the irregularity there are regularities. In other words there are something like 60 schemes and if we have one scheme and if we know to which scheme a verb belongs to, we can conjugate it. In other words, in these thin books you have something like 60 schemes and at the end a list of all verbs with a number that refers to the corresponding scheme. That reduces the complexity drastically. There are something like 2000 irregular verbs, but only 60 schemes.
Furthermore a lot of irregularities in the spelling only exists to maintain the pronunciation regular. G for instance is pronounced like the english g in grammar before o, a, u, but is pronounced like a voiced sh before e, i, see 18.104.22.168. Without an irregularity in the spelling, we would have dirigo, the g would be pronounced as g in english garden. In the infinitive form of dirigir the g is therefore pronounced like a voiced sh in english. If we want to maintain the phonetic value, we have to write dirijo, what is actually the correct spelling. This problem doesn't ocurr in the other personal endings es, e, imos, because in this case the g is followed by i / e and the g is pronounced as a voiced sh and therefore the spelling can remain regular. It is therefore questionable whether dirijo is irregular.
The verb tense with most irregular forms, in all roman languages, is the pretérito perfeito simples and some of them are completely irregular. Furthermore the most frequent verbs, in all languages, are the most irregular verbs. That is strange, because intuitevly one would suppose that the most used verbs are as well the best known verbs and everybody knows how to conjugate them. The five Portuguese modal verbs poder (can), ter que (must), dever (should), quer (to want) and saber (to know) are completely irregular, there is nothing left from the steem. The conjugation of these verbs has to be learned.
For the sake of simplicity the pronouns você / o senhor / a senhora bzw. vocês / os senhores / as senhoras, see 6.1.1 and 5, are not mentioned in the table. They require the third form singular / plural. It seems, at least we can find some comment on the topic in discussions forums on the the internet, that in some regions você / vocês is used with the second person singular of the verb, what doesn't agree with the standard grammar. (Although it would be as logical as the third person.) If the reader wants, he can add in the line ele / ela the pronouns você / o senhor / a senhora and in the line eles / elas the pronouns vocês / os senhores / as senhoras. For the sake of simplicity and to keep the table simple, we don't mention these pronouns.
modal verbs in pretérito perfeito simples
querer = to want
poder = can
ter que = have to
saber = to be able to (because it has been learned)*
ele / ela
eles / elas
* The english can / to be able to can have to different meanings. Someone can be able to do something, because there is nothing hindering him to do that. Someone can / is able to sleep, because there is no noise or other circumstances that prevents him from sleeping. However there is no learning process required to perform this action. But someone can theoretically be able to do something, because he has learned it before, but not necessarily in a concrete moment. Someone can have learned for instance to drive a car, but that doesn't mean that he can do it in a concrect moment. If he had a broken arm for instance, he can drive only in theory, but not in this moment see 15 modal verbs. In Portuguese different verbs are used in this different contexts. Poder if there is no hindrance, saber, if something has been learned.
Não pode dormir.
He can't / is not able to sleep.
Não sabe ler nem escrever.
He can't / is not able to read and write.
A sentence like "Não sabe dormir" would be absurd. There are people who can't sleep, but that has nothing to do with a lack of training.
It is obvious that the following verbs are very important and unfortunately completely irregular.
fazer = to do
vir= to come
ver = to see
pôr = to put
estar = to be*
ser = to bee*
dar = to give
For those who speak Spanish or Italian. Yes, Spanish and Italian have two verbs that corresponds to the English verb to be. No, the difference between ser (essere) and estar (estar) in Spanish is not the same as in Italian, but the difference between ser and estar in Portuguese is the same as in Spanish. As a rule of thumb we can say, that estar is used to describe a transitional state, ser is used to describe an inherent property, see as well 26. ficar (to remain), estar (to be), tornar-se (to become), ser (ser).
The strawberries are green, but I hope that they will change their colour.
There are several important exceptions to this basic rule, one the most important one is this: It is crystal clear that Lisbon is located in Portugal, this is an inherent property, however we can say "Lisboa está em Portugal". If it is possible to translate in English with "is located", then we use estar or ficar in Portuguese. Another exception is "Está morto", "He is dead". In general to be dead is a lasting, inherent property, but in this case the verb estar is used.
Whether something is definitely located at a certain place or only for a short time is irrelevant in Portuguese. (In opposite to Italian, where stare is used to describe the place where something usually is located and essere, if it is there for a short time.)
The bread is on the desk.
=> O pão está na mesa.
Lisbon is in Portugual.
=>Lisboa está em Portugal.
We still have to talk about ficar, that is an related issue, but we will do that in chapter 26.