I think the question should be why we don't use 'to' with the verbs make, let and have. This is very unusual in English and if you you use synonyms, they all use 'to'. I had my lawyer check the contract. > I got my lawyer TO check the contract. I made them do it again. > I forced/compelled them TO do it again. I let them leave early. > I allowed/permitted them TO leave early. Also, 'help' can take both forms: I helped him finish it. I helped him TO finish it. It's a really good question as to why these verbs don't use 'to' but I don't know the reason. They are a common subject in teaching, though, and are often studied together. I teach the unusual usage of 'let' and 'make' when I teach the 'have/get' somebody (to) do something structures. Also, if you use 'make' in passive voice, it uses 'to'. And 'let' can't be used in passive. I was made to do it again. I was allowed to do it again. (NOT I was let do it again.)

Jane- Your question does not have complete words. Sb and sth are not english words, and therefore your sentences do not have any meaning. 您的问题没有完整的单词。 Sb and sth 不是英文单词，因此你的句子没有任何意义。

Make, let, have are called causative verbs. They have their own special grammar. Causatives work with both active and passive voice. Active = causative verb + object + base form = I'm going to make my son do his homework Passive = causative verb + object + past participle = I'm going to have my nails done (by someone else)

I don’t think they can be missed out with ask and do. I asked him to clean his room. I forced him to clean his room. You can’t miss out the ‘to’.