There are ten Lakaras in Vyakaranam which represent the present tense, past tense and future tense as well as the imperative,potential,benedictory and conditional moods,
लट् वर्तमाने लेट् वेदे भूते लुङ् लङ् लिटस्तथा।
विध्याशिषोस्तु लिङ्लोटौ लृट् लुट् लृङ् च भविष्यति॥
लेट् is used only in Vedas. Other Ten Lakaras like लट् are used in Classical Sanskrit literature.
जय जय श्रीराधे