Pied Piping

• Cò air a bha an ad?
• Cò leis a tha am bata "who owns the stick"
• Cò aige a tha am bata "who has the stick"

Preposition stranding

Cò	bhruidhinn	thu	ris?
who	speak.pst	2sg	to.def
'Who did you speak to?'

Cò	an	cànanaich'	a	bhruidhinn	thu	ris?
who	the	linguist	wh-C	speak.pst	2sg	to.def
'Which linguist did you speak to?'

Pied-piping

Less natural compared to the preposition stranding version; Stress on cò is required; only possible with an echo question reading.

Rì	cò	a	bhruidhinn	thu?
to	who	wh-C	speak.pst	2sg
'To whom did you speak?'

Ri	cò	an	cànanaich'	a	bhruidhinn	thu	ris?
to	who	the	teacher	wh-C	speak.pst	2sg
'To which teacher did you speak?'

Pied-piping Inversion

The preposition must be definite.

Cò	ris	a	bhruidhinn	thu?
who	to	wh-C	speak.pst	2sg
'Who to did you speak?'

*Cò	rì	a	bhruidhinn	thu
who	to	wh-C	speak.pst	2sg

Cò	an	tidsear	ris	a	bhruidhinn	thu?
who	the	teacher	to.def	wh-C	speak.pst	2sg
'Which teacher to did you speak?'

*Cò	an	tidsear	ri	a	bhruidhinn	thu?
who	the	teacher	to	wh-C	speak.pst	2sg