Form and rules
How it works
Say/claim/explain can introduce that-clauses; tell normally needs a person object before the clause.
Promise/refuse/offer/agree often take to + infinitive.
Admit/deny/suggest commonly take -ing or a that-clause depending on the verb.
Advise/remind/warn often take object + to-infinitive; warn can also use against + -ing.
Do not assume all reporting verbs share one pattern; the complement is part of the verb's grammar.