A task asked me to conjugate the verb писать in present tense and I thought it whould have these endings: я пишу, ты пишёшь, он/она пишёт, мы пишём, вы пишёте, они пишут
But I checked the wiktionary and it tells me it is conjugated this way: я пишу, ты пишeшь, он, она пишeт, мы пишeм, вы пишeте, они пишут
Why doesn't the e change to ё??? When ю changes to у?
Ё changes into non-stressed "е" after ш and ж. You get same result with лизать: Я лижу, ты лижешь, мы лижем. When the word is one-syllable, so it's obviously stressed, it remains Ё. Although I can think of only one example: ты лжёшь, вы лжёте
Endings of the so-called first conjugation have ё if they are under stress, otherwise they have е. One must learn where the endings are stressed and where they are not, although endings, not including the -у/-ю for first person singular, are either all stressed or all not stressed.
You cannot have ю after "shibilants" (ж, ч, ш, and щ) so you have to write у there. Not after shibilants ю is written if there is a palatalised (soft) consonant before it or if there is a vowel (in this case there actually is a jot, which is a soft consonant, but it is not written because *йу changes to ю).
