Learn English Prefix 8: "pre-" or "pro-"

Meaning: These two prefixes mean "before" or "forward".

Pronunciation: "Pre-" is usually pronounced with a long "e" as in "see". "Pro-" can be pronounced with a long "o" as in "no" or "slow", but sometimes it is pronounced "a" as in "father". (For example, in the noun "progress".)

Example 1: Of course, a "prefix" is part of word added before another word! "We can make many new words by adding prefixes at the beginning."

Example 2: When we do something before an event so that bad things won't happen, we call it a "precaution". So we can say, "Keeping extra food and water at home is a precaution in case we have a terrible storm this winter".

Example 3: The word "proceed" means "to move forward". "If we finish step one of our project, we can then proceed to step two".

Other useful words: 
to precede - when something happens before another event 
a precedent - an example from before, often used in law 
predict - to guess what will happen in advance 
preexist - to be alive before something else 
progress (noun - pronounced PROgress) - good changes that have been made 
to progress (verb - pronounced proGRESS) - to make good changes 
probable - much more than "maybe" 
to probe - try to find out 
to process (pronounced PROcess) - to change something or make it ready for something 
to proclaim - to say something out loud 
a proclamation - something important that is said out loud 
to procure - to get or to buy 
to profess - to say loudly or openly