An auxiliary verb is a verb that supports another verb. It is derived from the Latin word auxilium, meaning help or aid. A sentence can contain more than one auxiliary verb.
In Dutch, we often need to place one or two extra words between the auxiliary verb and the independent verb:
- many auxiliary verbs require the little word te
- in the continuous we add aan het
There is, however, a substantial list of auxiliary verbs that behave the same in English: no funny extra words are needed. The auxiliary verbs are simply followed by a 'bare' infinitive. This also goes for auxiliary verbs that precede the past participle.
For most Dutch learners, using 'aan het' is not a problem. After all, it is only used in one particular grammar construction (the continuous).
The distinction between auxiliary verbs that require 'te' + infinitive and those that are followed by only a bare infinitive is more problematic. The logic is not as clear (if at all) as that of the 'aan het' construction. You can choose to randomly throw in 'te' whenever you feel like it, but you will only be right about half of the time. The only way to get around this is by learning the lists of verbs by heart ...
Questions? 
