My parents want me to work this summer. In German this is NOT an infinitive clause. The sentence must be broken down into a main clause and a subordinate clause. These pills help me to sleep. This verb usually functions like a modal auxiliary, i.e. the second verb is not preceded by zu .
Exceptions occur when the sentence is fairly long and complicated.
Diese Tabletten helfen mir schlafen. The doctor ordered me to breathe in deeply. The verb must go to the end of the infinitive clause with the zu between the prefix and the verb stem. In German this is NOT an infinitive clause. The sentence must be broken down into a main clause and a subordinate clause.