Well, you will know when to use -er when you refer as verbs with infinitives ending. What you will do is drop the -er from the infinitive and add the second conjugation present tense endings: -o, -es, -e, -emos, -en.
Explanation:
To use -ar you will use the first conjugation, for example, hablar, lavar, llamar.
La mujeres es pelirojo. Nos ensena periodismo. Es simpatico y trabajadora. ¿los turistas japones established Esperanto el autobus? Ustedes toman much as pruebas en la class de espanol
