@Arrowfar Decide takes a to-infinitival complement, while look forward to takes a noun phrase as a complement. In the former, to is an infinitive marker, while in the latter, to is a preposition.
Anonymous
Unfortunately, there is no way to reliably predict what sorts of complements these things take. You have to memorize it on a case-by-case basis.
Anonymous
It's not exactly random either, though. For example, we can point out that many verbs take to-infinitival complements, but very few take bare infinitival complements.
Anonymous
But for to-infinitival and gerund-participial clauses, you just have to memorize which verb takes which.
