You express that an action is currently happening using the zijn + aan het + infinitive construction. However, just like in English, not all verbs can be used in this continuous form.
Stative and Cognitive Verbs
Verbs that describe a continuous state, a mental process, or a perception are called stative or cognitive verbs. Because these verbs naturally describe an ongoing state rather than a physical action you actively execute, they cannot take the aan het construction.
Common examples include:
- weten (to know a fact)
- kennen (to know a person or thing)
- begrijpen (to understand)
- geloven (to believe)
- lijken (to seem)
Notice in the following example how the physical action (bestuderen) uses the continuous aspect, while the mental state (begrijpen) remains in the simple present tense.
| I am studying the very confusing photo, but I do not understand the optical illusion. | Ik ben de heel verwarrende foto aan het bestuderen, maar ik begrijp de optische illusie niet. |
| The photo is very confusing and we do not know the answer. | De foto is heel verwarrend en we weten het antwoord niet. |
Perception and the Mind
When talking about optical illusions and human perception, you will frequently use cognitive verbs. Verbs like lijken, bedriegen (to deceive), misleiden (to mislead), and zich verbeelden (to imagine) generally resist the continuous aspect.
| Because the perception is very complex, you seem to see two animals. | Omdat de waarneming heel complex is, lijk je twee dieren te zien. |
| He is staring at the photo, but he imagines that illusion. | Hij is naar de foto aan het staren, maar hij verbeeldt zich die illusie. |
Even when discussing something actively tricking your brain, use the simple present or past tense for the stative verb, while keeping the continuous aspect for active physical observations (like kijken).
| I was looking at the optical illusion, and I believe that my eyes deceive me. | Ik was naar de optische illusie aan het kijken, en ik geloof dat mijn ogen mij bedriegen. |
| He thinks that the optical illusion misleads my brain. | Hij denkt dat de optische illusie mijn hersenen misleidt. |