a) the 3rd binyan: the active conjugation hif’il
b) female plural form in male nouns – and vice versa

The 3rd binyan is the hif’il. hif’il means he activated. hif’il-verbs mostly bring about something. They are often transitive, i.e. they are often used with accusative-objects – eg to begin something. The vocalization a-i in present tense suggests that the verb is of the binyan hif’il.

hif’il-verbs in present tense:

singularplural
to…malefemalemalefemaleinfinitive
activateמפעילמפעילהמפעיליםמפעילותלהפעיל
maf’ilmaf’ilahmaf’ilimmaf’ilotlehaf’il
understandמביןמבינהמביניםמבינותלהבין
mevinmevinahmevinimmevinotlehavin
inviteמזמיןמזמינהמזמיניםמזמינותלהזמין
mazminmazminahmazminimmazminotlehazmin
know so.מכירמכירהמכיריםמכירותלהכיר
makirmakirahmakirimmakirotlehakir
beginמתחילמתחילהמתחיליםמתחילותלהתחיל
matchilmatchilahmatchilimmatchilotlehatchil
proposeמציעמציעהמציעיםמציעותלהציע
matziamatziahmatzi’immatzi’otlehatzia
leadמדריךמדריכהמדריכיםמדריכותלהדריך
madrichmadrichahmadrichimmadrichotlehadrich
showמראהמראהמראיםמראותלהראות
mar’ehmar’ahmar’immar’otlehar'ot
promiseמפתיחמפתיחהמפתיחיםמפתיחותלהפתיח
maftiachmaftichahmaftichimmaftichotlehaftiach
lowerמורידמורידהמורידיםמורידותלהוריד
moridmoridahmoridimmoridotlehorid

Note: (the following points refer to present tense)

  • the vocalization of and the female forms of verbs with a chet or ayin as third consonant of the shoresh, eg hu matzia, he proposes, hi maziah (stress on last syllable), she proposes.
  • the vocalization of verbs with a yud as first consonant of the shoresh, as in hu morid, he lowers – the yud is changed into a vav.