wrth
by, at (proximity); while
Mae rhywun [wrth] y drws = Someone's [at] the door.
Roedd e'n sefyll _wrth_ y byrddau 'na = He was standing _by_ those tables.
Ro'n i'n teimlo'n hapus [wrth] siarad รข fe = I felt happy [while] talking to him.
by
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