Hedging and stance in academic Spanish: cabe señalar, parece que, sería conveniente que

Impersonal formulas and their agreement

Se observa que, se puede afirmar que, cabe señalar que and cabe suponer que have no subject you can pluralise: the que clause is the subject, so the verb stays singular. Write Se observa que los precios suben, never *se observan que. With a plain noun, se is a passive and the verb agrees: Se observan diferencias. The same holds for se puede afirmar que and cabe señalar que: the que clause is the subject, so puede and cabe stay singular. With a plural noun the verb agrees again: Se pueden observar diferencias. Habría que considerar uses impersonal haber, so it is never *habrían que. The verb parecer has two patterns: Parece que los datos indican un cambio (impersonal, singular) and Los datos parecen indicar un cambio (the data are the subject, plural).

The conditional of mitigation

To soften an opinion or a proposal, use the conditional: Yo diría que, Habría que considerar, Cabría preguntarse si, podría deberse a, no sería exagerado afirmar que. After sería conveniente / recomendable / deseable que, the verb goes in the imperfect subjunctive: Sería recomendable que los autores ampliaran la muestra. The present subjunctive is heard in parts of Latin America, but the imperfect is the standard in writing, and the indicative or the conditional there is a mistake. Compare hay que revisar (a blunt obligation) with habría que revisar (a softened suggestion).

Parece que / no parece que, es evidente que / no es evidente que

English "it seems that" and "it doesn't seem that" use the same verb form, so the mood switch is easy to miss. In Spanish the negation changes it: Parece que el método es válido, but No parece que el método sea válido. The same happens with es evidente que (indicative) and no es evidente que (subjunctive). A value judgement also takes the subjunctive: Parece lógico que se dude. Likewise es posible que never takes the indicative, so "it is possible that he is" is Es posible que sea, not *es posible que es. The adverbs quizá, tal vez and posiblemente accept both moods; the difference in nuance is slight, and neither is a mistake.

The plural of modesty

In English a single author writes "I" or avoids the subject with a passive, and "we" can feel odd. Spanish academic writing uses the first person plural normally, even for one author: En este trabajo analizamos, Como hemos visto, Nos proponemos demostrar. It is a convention of the text, not a claim about several people, and it is not obligatory (analizo is also correct). What matters is consistency: keep one choice through the paper and do not switch between analizamos and he visto in one paragraph.

Softening disagreement and marking certainty

To disagree without confrontation, soften the verb or the scope: No estoy del todo de acuerdo con, No comparto del todo, hasta cierto punto, en parte. A concession with si bien takes the indicative, and a second clause with cabe matizar que adds the nuance: Si bien es cierto que la muestra es pequeña, cabe matizar que los resultados coinciden. For a categorical claim backed by data, use sin duda, evidentemente, es innegable que or no cabe duda de que (always with de). For your own view, a mi juicio and desde mi punto de vista are equivalent.

Same-strength choices

Many hedges are interchangeable: cabe señalar, cabe destacar, conviene destacar and es preciso señalar have the same strength, and so do a mi juicio and en mi opinión, or es posible que and puede que. Choose by register and rhythm, not by grammar. The grammar that matters is the mood, the agreement and the tense after the conditional. One real contrast of meaning: conviene destacar que + indicative states a fact worth noting, while conviene que + subjunctive recommends something.