Dead Letters — Teach and Solo Gameplay

About Dead Letters, from BoardGameGeek:

In Dead Letters you play as a 1915 Dead Letter Office employee who has fallen asleep at your desk. The game is a dreamy landscape of "postage punk" aesthetics and early 20th century mail motifs. But at its heart, it's a simple word game. Contribute letters to a central word to change it. Some letters give you special abilities. Figure out how you can outsmart your opponents with chain effects and Red Letters in order to rid yourself of all your cards and win! Or play cooperatively, placing cards on two central boards to make them both read the same word, without getting stuck (every card you play has to make a new word). -description from designer