Verb asseoir

"Asseoir" (to sit) (and rasseoir (to resit)) is well known to have two forms of conjugation: j'assois and j'assieds. Is there a preference in the use of these forms? Let's say it right away, both forms are perfectly correct. However, we can see that the forms in "ie" are more distinguished than the forms in "ey". Note however that the future and the conditional *j'asseyerai and *j'asseyerais are no longer used.

On imperative, we'll say "assieds-toi" or "assois-toi" but never *"assis-toi". This "assis" is an unusual form of the indicative present tense from the seventeenth century, it is not used anymore nowadays.

In addition, the presence of the etymological "e" except in the indicative present and future tenses.

The 1990 reform

In the 1990 reform, the Académie française proposes to drop the etymological "e" of "asseoir" and writing this verb assoir. However, this form seems far from being adopted and it is preferable to keep this e.