a) the subjunctive: to be in past tense + verb in present
b) sequence of tenses and reported speech
c) the derivation of nouns from pa’al-, pi’el- and hif’il-verbs
d) the imperative – eg go!

Subjunctive is a simple thing in Hebrew. It is formed with the verb “to be” + conjugated verb in present tense.

Note: subjunctive past tense and present tense are identical in Hebrew.

Examples:

I had invited him, if he had been in town. הייתי מזמין אותו, אם הוא היה בעיר
hayiti mazmin oto, im hu hayah ba’ir
can also mean: I would invite him, if he were in town.