What is the correct way to use infinitive after the verb “help”: with or without “to”?
Please, help me to understand this.
Please, help me understand this.
The particle “to” is not wrong in this sentence, but it is unnecessary. I would recommend against using it.
The phrase “to understand” can be interpreted as a special case of the infinitive; a kind of future infinitive or impersonal future tense. In that context, the first sentence means, essentially, “please help me develop an understanding of this (in the future)”. While that may be technically correct, it adds nothing to the meaning of the sentence.
To add some weight to my argument, the COCA lists 142 entries for “help me understand” versus only 18 for “help me to understand”. The results are similar for other constructions involving “help me …” versus “help me to …”.
I think that the confusion stems from the way you must use the infinitive in other cases, for example: “I want to understand this”, or “I am trying to understand this”. In these cases, the particle is an absolute neccesity.