Primary (1°) phosphines, with the formula RPH, are typically prepared by alkylation of phosphine.  Simple alkyl derivatives such as methylphosphine (CHPH) are prepared by alkylation of alkali metal derivatives MPH (M is Li, Na, or K).  Another synthetic route involves treatment of the corresponding chlorophosphines with hydride reagents.  For example, reduction of dichlorophenylphosphine with lithium aluminium hydride affords phenylphosphine (PhPH).
Primary (RPH) and secondary phosphines (RRPH and RPH) add to alkenes in presence of a strong base (e.g., KOH in DMSO). Markovnikov's rules apply. Similar reactions occur involving alkynes. Base is not required for electron-deficient alkenes (e.g., derivatives of acrylonitrile) and alkynes.