In the present tense, German verbs whose infinitive stem ends in -d:
add -est and not -st in the "du" form
add -et and not -t in the "er/sie/es" form
add -et and not -t in the "ihr" form
Verbs with a stem in ending in -d include:
A-E: ahnden (to avenge, to punish), aufbürden (to encumber), baden (to bathe), beenden (to end), beneiden (to envy), bilden (to form), binden (to tie), blenden (to dazzle), downloaden (to download), dulden (to tolerate), enden (to end), erkunden (to find out, to reconnoitre), ermorden (to murder), ermüden (to tire)
F-M: fahnden (to search for), sich gebärden (to conduct oneself), gefährden (to endanger), gründen (to found), kleiden (to dress), landen (to land), melden (to report), münden (to flow into, to lead)
N-S: pfänden (to impound), reden (to speak), roden (to clear), runden (to round), schaden (to damage), schmieden (to forge), schneiden (to cut), schulden (to owe), senden (to send), sieden (to boil), spenden (to donate), stranden (to run aground, to be stranded), stunden (to give someone time to pay)
T-Z: verabschieden (to say goodbye to), verfremden (to defamiliarize), vergeuden (to waste), verschwenden (to waste), verschwinden (to disappear), verwunden (to wound), vollenden (to complete), wenden (to turn), zünden (to ignite).