construct

In Hebrew, whenever two (or more) nouns appear together (either by juxtaposition or by means of a maqqef), they are said to be in a “construct relation” to one another. You will use the key word “of” in your translation (cf. genitive). The following would be translated, “sons of Joseph”.

יֹוסֵף בְּנֵיNote the sere-yod vowel; a sure sign of a noun in the construct state. 

The first noun is said to be in the construct state; the last noun is said to be in absolute state.  (more | video)

Note:

1. a noun ending in sere-yod, is always a masculine plural noun in construct;
2. the entire construct chain is to be considered definite when the last noun is definite.