"We often ride horses in April."
Translation:A menudo montamos a caballo en abril.
In English you need to include the personal pronoun because if only the verb was used, e.g. speak, you wouldn't know whether it refers to I, you, we or they. The same goes for French, where (je) parle, (tu) parles, (il/elle) parle and (ils/elles) parlent are pronounced the same, so the personal pronoun must always be included.
In Spanish, Italian and Slavic languages the personal pronoun can be omitted and usually isn't used in everyday speech or writing because verbs in these languages have a specific form for every person (1st person singular, 2nd person singular, etc.).
For example, in Spanish you have:
You can see that there's no ambiguity when using only verbs, so there's no need to include the personal pronoun. :)