Aphabetic letter pairs in words

YP = yup

YQ - Yuraq Yuraq

The obscure Bolivian mountain so nice they named it twice!: Yuraq Yuraq - Wikipedia

YR: yellowhammer

YS: yes

YT: yurt

YU = you

YV = Anton Yurikov, a Russian candidate from the Liberal Progressive Party who received 5.8% of the vote for the Cheryomushki single-mandate constituency for the state Duma in the 2016 electio(.

Disclaimer: Any resemblance to a political commentary is inadvertent and coincidental.)

YZ - yaz (A drug though to this Old New Englander it will always mean Red Sox player Carl “Yaz” Yastrzemski)

YW = yew

(Annie, you skipped a couple. YV and YY do look a bit alike.)

(Ooops. Sorry)

YY - yearly

Now on to ZA

YX = yex.

a hiccup or belch.

NOW on to ZA.

ZA - zebra

ZB - Zab

ZC = zinc

ZD = zeroed

ZE = zygote

ZF - zarf

ZG: zigzag

ZH: zoomorph

ZI = zombi