There are two prefixes spelled en-. One comes from the Latin suffix in-, has as its basic meaning “into or onto,” and chiefly forms verbs. Thus encapsulate means “to put into a capsule,” and enplane means “to get on an airplane.” This same en- also has the meanings “to cause to be,” as in endear, and “to cover or provide with,” as in enrobe. It sometimes has intensive force, as in entangle. En- has a variant spelling in-, which is why we have pairs like enclose/inclose and enquire/inquire.
1
The second en- goes back to Greek and means “in, into, within.” It occurs chiefly in scientific terms like enzootic, which is used of diseases and means “affecting animals within a particular area.”
2
Both suffixes change from en- to em- before b and p: embroil, empathy.
