葡萄牙语自复动词：自复与非自复含义 (me, te, se)

A truly reflexive verb denotes an action the subject performs directly upon itself (e.g., Eu me lavo - 'I wash myself'). A pronominal verb (also called inherently reflexive) grammatically requires a reflexive pronoun, but the action isn't literally 'on oneself'; it often indicates a change of state, an emotion, or a verb that simply exists in this form (e.g., Eu me arrependo - 'I regret'). The pronoun is an intrinsic part of the verb's structure and meaning in both cases.

This is primarily a matter of memorization, as it's not always predictable. Many common pronominal verbs require de (esquecer-se de, lembrar-se de) or com (preocupar-se com), while others might take por (apaixonar-se por). When learning a new verb, always check if it's pronominal and, if so, which preposition it governs. Often, there's a non-reflexive counterpart that takes a direct object, while the pronominal version takes a prepositional object.

Yes, esquecer and lembrar can be used transitively without se, meaning they take a direct object. For example, Eu esqueci o livro ('I forgot the book') and Eu lembrei o nome ('I remembered the name' or 'I reminded the name, less common for 'remembered'). When used pronominally with se, they become esquecer-se de and lembrar-se de, taking a prepositional object: Eu me esqueci do livro ('I forgot about the book'), Eu me lembrei do nome ('I remembered the name'). Both forms are correct but have different grammatical constructions and subtle semantic nuances.

Verbs behave differently across languages. In Portuguese, acordar is simply an intransitive verb meaning 'to wake up'. There is no acordar-se. The equivalent of 'I wake myself up' is still Eu acordo, or Eu me levanto ('I get myself up'). It's a specific linguistic convention of Portuguese, so you should avoid Eu me acordo.

In informal Brazilian Portuguese, proclisis is highly prevalent and often used even at the start of sentences (e.g., Me ajuda!). While common and accepted in spoken and informal written contexts, formally, standard grammar still dictates that a sentence should not begin with an unstressed pronoun. For formal writing, or if you aim for universal correctness, it's safer to avoid starting a sentence with me, te, se, nos, vos unless there is a clear proclitic trigger (like Não me ajuda or Sempre se ajuda). However, in daily interaction in Brazil, starting with the pronoun is ubiquitous.

Both use the same reflexive pronouns. A reflexive action means the subject performs the action on itself (Eu me lavei - 'I washed myself'). A reciprocal action means two or more subjects perform the action on each other (Nós nos abraçamos - 'We hugged each other'). The context, and often the plurality of the subject, usually clarifies the meaning.

Yes, several verbs in Portuguese exist almost exclusively in their pronominal form. Examples include arrepender-se (to regret), queixar-se (to complain), suicidar-se (to commit suicide), and dignar-se (to deign). For these verbs, omitting the reflexive pronoun results in an ungrammatical construction. When learning these, always learn them with the se.

The impersonal 'se' is used to form indefinite subject constructions, often translated as a passive voice without specifying the agent (e.g., Vende-se casa - 'A house is sold' or 'House for sale'). The action is not performed by the 'house' on itself. The verb is always in the third person singular. In contrast, reflexive 'se' indicates that the subject itself is performing the action on itself, and the verb's conjugation matches the subject (e.g., Ele se veste - 'He dresses himself'). They look similar but serve distinct grammatical functions. The impersonal 'se' doesn't have a plural subject (e.g. you wouldn't say 'Vendem-se casas' for plural 'houses'). Instead, the verb agrees with the direct object, so it would be Vendem-se casas ('Houses are sold'), where 'casas' becomes the grammatical subject.