In Czech grammar, the progressive aspect is expressed by using the verb “být” (to be) in the present tense, followed by the preposition “na” and the infinitive form of the main verb. This construction is used to talk about ongoing actions or situations, similar to the English present continuous tense.

For example, to say “I am reading a book”, we would say “Jsem načítání knihu”, using the present tense of “být” (jsem), the preposition “na”, and the infinitive form of “načítat” (to read).

The progressive aspect can also be used to express future actions or plans. For instance, to say “We will be studying tomorrow”, we would say “Budeme na studování zítra”, using the future tense of “být” (budeme), the preposition “na”, and the infinitive form of “studovat” (to study).

It’s important to note that the progressive aspect is not commonly used in Czech and is often replaced by other verb forms or constructions.