Lexical usage

Beside ὥσπερ (ἂν) εἰ - albeit rarely - καθάπερ (ἂν) εἰ is also possible.
The meaning of ὥσπερ (ἂν) εἰ can sometimes be weakened from a conditional comparison to a simple comparison, thus becoming synonymous with ὥσπερ or ὡς ‘like’. In this case many editors write it as one word: ὡσπερεί, ὡσανεί or ὡσπερανεί. In a later phase the meaning ὡσπερεί further weakens to ‘as it were’.
Comparative conjunctions are often combined with other conjunctions in order to compare the state of affairs in the main clause with another state of affairs. The following combinations occur:

• [comparison with a point in time] ὡς ὅτε or ὡς ὁπότε ‘as when’ (mostly in epic comparisons);
• [comparison with a hypothesis] ὡς εἰ or ὥσπερ εἰ ‘like if, as if’;
• [comparison with a manner] ἢ ὡς ‘than as’ (standard of comparison + manner).

Translation tips

Translate this construction as follows:

• ὥσπερ (ἂν) εἰ or καθάπερ (ἂν) εἰ ‘as if, just as if, even as…’;
• ὡσπερεί, ὡσπερανεί ‘just as’.

Syntactic usage

The use of moods and tenses corresponds to that of conditional clauses, introduced by εἰ. In practice mainly the optative (of the possible condition) occurs, irrespective of the time and mood of the main clause.

Historical background

We are dealing here with an elliptical construction: a comparison is in fact being made with a condition. This means that between ὥσπερ (ἂν) and εἰ the same verb as that in the main clause could be repeated. Because of this, ἄν is used when the condition is plausible or possible. This also explains why ὥσπερ ἂν [sec. ind./conj./opt.] εἰ is more common than ὥσπερ [ind.] εἰ.

Varia

Latin uses quasi or uelut si with a comparable meaning.