In English, pronouns are completely separate from every other word (with the exception of shortened common words like "gimme"), but in many languages one word can contain the subject, direct object, and indirect object.
Subject pronouns in romance languages like Spanish aren't necessary. Bailo, "I dance", is sufficient to say "I dance"; yo bailo is redundant and the subject yo, "I", only serves to emphasize that _I_ am the one that's dancing. There are cases where just the verb is ambiguous (especially as fewer conjugations in a tense are used -- usted es, "you are" (singular polite) is necessary because es can also mean "he is", "she is", "it is", etc.
Spanish doesn't normally attach pronouns; however, they DO attach both indirect and direct pronouns in the cases of positive commands and infinitives -- see: leerlo, "to read it" (lo being the direct object masculine pronoun for an "it" or a "he"); quererte, "to love you" (te being the direct and indirect pronoun "you"); dime, "say to me" (me being the direct and indirect object); dímelo, "say it to me".
Arabic also frequently takes advantage of bound pronouns -- كامته, kalamtuh, "I spoke to him" (uh being "to him"); خبرني, xabbaranii (nii indicating "to me"). This is an element of many Semitic languages, like Amharic; however, the bound pronouns are much harder to find. Though it's easy to see ስጪኝ, sïčiñ (the ñ being "to me"), this pronoun isn't always at the end -- see አልነገረንም, alnägäranïm, "they didn't tell us" (the n towards the end meaning "to us"; the last im is a negative market), or ይጠብቁታል, yït'äbbïk'utal, "they're waiting for him" (yït'äbbïk'allu, ይጠብቃሉ, "they're waiting"; through complex conjugation the t used to indicate "to/for him" gets a further suffix afterwords). Note that only one pronoun can add onto a verb (as opposed to the Spanish above and dímelo.
Our final example of the night is the most different -- Cherokee. Bound pronouns are used not only for subjects, but a different set of pronouns exist for different subject-object pairs (I->you, him->them,etc.). Base pronouns will produce simple sentences like ᎨᎦ g-ega, I am going (the first g in this case indicating a first person singular subject), or ᎣᏍᏕᎦ osd-ega, "the two of us are going" (the osd in this case indicating that the speaker and someone else excluding the listener are going). When you get into more complex statements involving a direct/indirect object, it's still just one pronoun: ᏍᎩᏃᎯᏏ, sginohisi, "You tell me" (the sgi being "you, to me"); ᎬᏃᎯᏏ, gvnohisi, "I tell you" (the gv being "I, to you"). This pronoun adds on along with other various elements to a verb to give one complete thought; hence, the verb is the most important element of the Cherokee language.