Verb + de + infinitive
accepter
deno preposition
The constructions
deaccepter de + infinitif
Meaning : to agree to do
Elle a accepté de nous aider.
Do not writeElle a accepté à nous aider.
no prepositionaccepter quelque chose
Meaning : to accept something
Il a accepté notre proposition.
Why
Accepter de takes de before an infinitive, even though its synonym consentir à takes à. Before a noun, accepter is direct. English « agree to » and Chinese 同意 are no help: you have to remember de.