“Me alegro DE que” but “pienso QUE”
CEFR C1
“Si hubiera sabido…”: the past that did not happenThe unreal past: “si hubiera sabido, habría venido”, and the mixed conditions where one…“Por más que lo intente”, “a fin de que sepas”The conjunctions that always take the subjunctive —“para que”, “a fin de que”, “sin…What you can say to whomTelling apart what belongs in a message to a friend, in an email to a stranger and in a…“Por” and “para”, the hard halfThe pairs where both are possible and the meaning changes: “estar por” against “estar…“Ponerse”, “volverse”, “hacerse”, “quedarse”: four “become”Choosing among the four: “ponerse” for a passing state, “volverse” for a lasting change…What people write and what people sayWhat changes between the two: the “ser” passive, “cuyo”, the tenses that survive only in…The rule, in three lines
Some verbs carry de into the clause and some refuse it: me acuerdo de que, estoy seguro de que, me di cuenta de que against pienso que, creo que, dijo que. The test is to swap the clause for eso: if you would say de eso, keep the de.
The usual slip. Both at once: pienso de que adds a preposition that is not there, and me acuerdo que drops one that is.
Why it catches you out. English never puts a preposition in front of a “that” clause — “I'm sure that…”, “I remember that…” — so there is no signal to copy. And you will hear native speakers make both mistakes, which takes away the last guide you had. The good news is that the “eso” test is mechanical and works every single time.