Tenses are an important aspect of Estonian grammar as they help us express the time and duration of an action or state. In Estonian, there are three simple tenses: present, past, and future. These tenses are formed by adding specific suffixes to the verb stem.

The present tense is used to describe actions or states that are happening at the moment or are generally true. It is formed by adding the suffix “-b/-v” to the verb stem.

The past tense is used to describe actions or states that have already happened. It is formed by adding the suffix “-s/-sid/-nud” to the verb stem, depending on the vowel harmony.

The future tense is used to describe actions or states that will happen in the future. It is formed by adding the suffix “-n/-vad” to the verb stem.

In addition to these simple tenses, Estonian also has compound tenses, such as the perfect, pluperfect, and future perfect. These tenses are formed by using the auxiliary verbs “olema” (to be) and “olema hakkama” (to become).

Overall, understanding tenses in Estonian grammar is essential for expressing time and duration accurately in the language.