1. La--You have to think of gender. Calculadora ends in an a (Anything that ends in D-ION-Z-A is feminine and anything that ends in L-O-N-E-R-S is masculine)
2.Las--Gender again...regalas ends in an a but it is not la because it is plural.
3. El--Gender makes it masculine this time. This one could also be un becuase un is a and el is the, so it really just depends!
4. Los--unos is some and los is the (plural). It is masculine because boligrafos ends in -os!!
Ernesto <u>se</u> afeita todos los días. Yo <u>me</u> visto con suéter en el invierno. Manuela <u>se</u> toma un batido de fresa. Carmen y Elena <u>me</u> visitan desde ayer. Tú <u>te</u> acuestas siempre a las 9.