False friend
A word in a foreign language which looks very much like a word in your own language but which has a very different meaning.
Finite verb
A label applied to a verb-form which is marked for tense. A finite verb has the marking –s in the simple present tense. Note that this happens only when the subject is in the third person singular.
So for example in James works, the verb-form works is finite. In the past tense, tense is marked either by the ending –ed or by a change in the inner vowels of the verb.
Foreign plural
A plural form which has been imported directly from a foreign language. English has dozens of foreign plurals. Examples include radii (plural of radius) and phenomena (plural of phenomenon).
Foreign plurals often confuse English-speakers because they may have difficulty remembering which form is the singular and which is the plural.
Free morpheme
A morpheme which can stand alone to make a word all by itself. For example, the English verb happy is a free morpheme because it can stand alone. A free morpheme may sometimes combine with other morphemes in a larger word. For example, happy can combine with the morpheme un to form the larger word unhappy.