Probably one of the most unusual, complex, curious, yet frustrating features of Portuguese that I’ve found is the use of clitic pronouns. In theory, while complex, the rules are quite straight forward. If there’s a negation, put it at the beginning. Talking about a “would” or “will”? In the middle! If none of those, bring it to the end. But if you have an r, z or s, cut it off and bring in an l. The only irregularity I’ve found is that somehow “he wants it” ends up becoming “quere-o”.
Despite all that, what I’ve found is that they’re not even used that often. Let’s use Google to demonstrate this. The phrase “he brings it” or “ele tra-lo” yields 6 pages. The aforementioned “quere-o” 7. I did it “eu fi-lo” with a bit more at 13 pages. Meanwhile the English and Spanish versions of those yield way more results. I know that English and Spanish are spoken more, but considering how some of the results on Portuguese phrases weren’t even in Portuguese and when they were, they were articles about the grammatical rules, I have to wonder…
Do the Portuguese just dislike using the clitic pronouns?
Merged pronouns (e.g. -lho, -to…), and pronouns placed in the middle of verbs (future and conditional) are universally avoided. Any pronouns used reflexively or reciprocally are unavoidable. Otherwise, we’re very consistent in using 1st and 2nd-person pronouns (-me, -te, -nos and -vos), along with the indirect 3rd-person pronouns (-lhe/-lhes), but have weird patterns of use for direct 3rd-person pronouns, which seem to be the focus of your post.
The issue with direct 3rd-person pronouns is that all the complexity around this topic is concentrated in them, such as the rules about adding -L or -N to the pronoun, or the exceptions quere-o and tem-lo. So, those are mostly the cases that people tend to avoid. We’ll say eu vejo-o, but avoid tu vê-lo; or say tu conheceste-a, but hesitate with eles conheceram-na. Note that in all these examples, the pronouns are placed after the verb. In cases where we can or must place them before, no modifications are needed, so there’s usually no issue there.
So, in short, the Portuguese use clitics A LOT, but preferably only in easy mode.
Here’s a funny thing though. It looks like in Brazil they do say qué-lo not quere-o https://www.conjugacao.com.br/verbo-querer/ (scroll down to ” Conjugação com pronome oblíquo átono “)
This then brings the question, what’s done instead? And is there a pattern? In the case of mesoclise which is the most unusual, this seems to be circumvented by, correct me if I’m wrong, simply opting for en/proclise OR by using simpler verbal constructions to go around it. “eu manda-lo-ia” → “eu mandava-o” / “eles dar-me-ão” → “eles vão me dar”. This is, if I recall correctly, talked about in the PP units and is mentioned in other online sources.
However, the alternatives to the other examples aren’t ever mentioned neither here nor elsewhere. Like, I would assume that simple things like “eles conheceram-na” and “dá-mo!” are things that would be brought up constantly in every day speech.
@Jemmy, there’s a pattern to replace merged pronouns, where people will usually keep the indirect object pronoun. Some examples:
Dá-mo → dá-me
Dou-to → dou-te
Dei-lho → dei-lhe
For other cases, it really varies depending on context, the form at hand, the speaker’s preferences, etc. People might mistakenly make up forms that don’t exist (e.g. tens-o instead of tem-lo), drop the pronouns altogether (e.g. simply ele quer instead of ele quere-o), use alternative pronouns if suitable (e.g. eles conheceram-se instead of eles conheceram-na), use the pronouns with an infinitive instead of a conjugated form (e.g. tu estás a vê-lo instead of tu vê-lo), or simply restate the object (e.g. Não encontro a caneta. Viste a caneta? instead of Não encontro a caneta. Viste-a?). If in doubt, you can always go for the latter.