“Creo que es” but “no creo que sea”
CEFR B1 · part 1
edumaterial's parts within the level. The European framework does not subdivide them.
“Quiero que vengas”: the subjunctiveForming the present subjunctive and using it after verbs of wanting, asking, feeling and…Giving orders, and being polite about itForming commands for “tú”, “usted”, “vosotros” and “ustedes”, positive and negative…Three ways of saying “will”Choosing between the present, “ir a” + infinitive and the simple future, and knowing…“Pedir” or “preguntar”: one “ask”, two verbsUsing “preguntar” for a question and “pedir” for a request: “le pregunté la hora”…“Quedar”, “quedarse”, “dejar”Four everyday verbs that English packs into “stay”, “leave”, “keep” and “arrange”…“Ser” or “estar”: two verbs for one “to be”Choosing between “ser” and “estar” in everyday sentences: who you are and what you are…The rule, in three lines
Creo que es tarde — you are asserting it, so indicative. No creo que sea tarde — you are denying it, so subjunctive. The same flip happens with pensar, parecer, es verdad que and está claro que: affirmative takes the indicative, negative takes the subjunctive.
The usual slip. Applying “subjunctive after que” as a blanket rule, and saying creo que sea.
Why it catches you out. English marks doubt with a modal or with intonation — “I don't think it IS” stays in the indicative — so there is no signal in your language to copy. Spanish marks it in the verb itself, and the switch is mechanical: put a “no” in front of “creo” and the other verb has to move.