Sunday Times

[bravodeltic]

Help on a couple please
12a one very bright teacher is blocked by university (6) ?i?i?s
20d save a great deal for servant (7) b?????s
21d copy one bird and others will follow (7) e?????e

Thanks

[Oldred]

12a Sirius

[donny48]

21 emulate

[dannyk13]

20d.Buttons

[Lie-in King]

12a Sirius (star) - 'Sir' + 'is' (blocked by) 'u(niversity)'
20d Buttons (page boy) - 'but' (save) + 'tons'
21d Emulate - 'emu' + 'et al' (others, back)

[fiction-factory]

sirius?

[Oldred]

20d Buttons