Table: wtatier_i_tournaments
Columns: tournament
surface
week
winner
finalist
semi_finalists

Question: Which Semi finalists had a Week of may 15?
SQL: SELECT "semi_finalists" FROM wtatier_i_tournaments WHERE "week" = 'may 15'

Question: Which Finalist has a Semi finalists of monica seles conchita martínez?
SQL: SELECT "finalist" FROM wtatier_i_tournaments WHERE "semi_finalists" = 'monica seles conchita martínez'

Question: Which Tournament has a Semi finalists of monica seles sandrine testud?
SQL: SELECT "tournament" FROM wtatier_i_tournaments WHERE "semi_finalists" = 'monica seles sandrine testud'

Question: Which Surface has a Semi finalists of conchita martínez arantxa sánchez?
SQL: SELECT "surface" FROM wtatier_i_tournaments WHERE "semi_finalists" = 'conchita martínez arantxa sánchez'

Question: Which Tournament has a Semi finalists of mary pierce elena dementieva?
SQL: SELECT "tournament" FROM wtatier_i_tournaments WHERE "semi_finalists" = 'mary pierce elena dementieva'

Question: Which Tournament has a Semi finalists of martina hingis joannette kruger?
SQL: SELECT "tournament" FROM wtatier_i_tournaments WHERE "semi_finalists" = 'martina hingis joannette kruger'