In linguistics, modal particles are always uninflected words, and are a type of grammatical particle. They are used to indicate how the speaker thinks that the content of the sentence relates to the participants' common knowledge or add mood to the meaning of the sentence. Languages that use many modal particles in their spoken form include Dutch, Danish, German, Hungarian, Russian, Telugu, Nepali, Indonesian, Chinese and Japanese. The translation is often not straightforward and depends on the context.
Main article: German modal particles
The German particle ja is used to indicate that a sentence contains information that is obvious or already known to both the speaker and the hearer. The sentence Der neue Teppich ist rot means "The new carpet is red". Der neue Teppich ist ja rot may thus mean "As we are both aware, the new carpet is red", which would typically be followed by some conclusion from this fact. However, if the speaker says the same thing upon first seeing the new carpet, the meaning is "I'm seeing that the carpet is obviously red", which would typically express surprise. In speech the latter meaning can be inferred from a strong emphasis on rot and higher-pitched voice.
In Dutch, modal particles are frequently used to add mood to a sentence, especially in spoken language. For instance:
Modal particles may be combined to indicate mood in a very precise way. In this combination of six modal particles the first two emphasise the command, the second two are toning down the command, and the final two transform the command into a request:
Because of this progressive alteration these modal particles cannot move around freely when stacked in this kind of combination. However, some other modal particles can be added to the equation on any given place, such as gewoon, juist, trouwens. Also, replacing the "imperative weakener" maar by gewoon (indicating normalcy or acceptable behavior), changes the mood of the sentence completely, now indicating utter frustration with someone who is failing to do something very simple: