but

а

However, although, nevertheless, on the other hand (introducing a clause contrary to prior belief or in contrast with the preceding clause or sentence)

• I know you know, but do you know I know you know?

  Я знаю, что ты знаешь, но знаешь ли ты, что я знаю, что ты знаешь?

  Tatoeba · Ooneykcall · CC BY 2.0 FR

• But what if he says no?

  А что, если он скажет "нет"?

  Tatoeba · Hybrid · CC BY 2.0 FR

а

On the contrary, rather (as a regular adversative conjunction, introducing a word or clause in contrast or contradiction with the preceding negative clause or sentence)

а

Except that (introducing a subordinate clause which qualifies a negative statement); also, (archaic) with omission of the subject of the subordinate clause, acting as a negative relative, "except one that", "except such that"

а

Only; solely; merely

а

Used at the beginning of a sentence to express opposition to a remarkредкое

а

Used to link an interjection to the following remark as an intensifierредкое

а

Without it also being the case that; unless that (introducing a necessary concomitant)редкое

а

Except with; unless with; withoutредкое

а

Untilредкое

а

Thatредкое