Wǒ mǎi le sān běn shū, lìngwài hái mǎi le liǎng zhī bǐ.
I bought three books, and also two pens.
Tips
grammar
另外 has two uses: (1) as a conjunction meaning 'in addition' at the start of a sentence, (2) as an adjective meaning 'other/another' before a noun (另外一个 = another one).