i knew it'd come in handy some day.
As Jebus said, Latin is an inflected language: rather than a dependence on word order, such as English (highly, highly order-dependent), Latin structures itself around suffixes that define words' syntax within a given sentence and context.
Ego is the first person singular pronoun, "I." However, because Latin conjugates its verbs very definitely according to person (and tense), pronouns are often unnecessary. Consumo ("to eat") then, is present active first person singular, as designated by the "-o" suffix. i doubt ego was ever used except as an intensifier in conversational Latin. Suffixes, though, are the key to learning and understanding the language. For verbs, there are endings for each person (6) in each tense (6), divided up into multiple standards of conjugation (4), which of course all come in active and passive form. And that's just verbs. Word order is of little ultimate importance, though there are tendencies in word placement and of course breathing room to rearrange for emphasis.
But, while decently complex for its many suffixes, Latin is in no way the most complicated. A few Native American languages are expansively inflected, Navajo for example being powerful enough to use as code during World War II.