算【suàn】

算 means "count as". It gives a judgment, and usually a careful one: the thing qualifies, but only just, or more or less.

不算 and 算不上

The negative is the most common use: something doesn't really reach the label. 不算 plays down a degree; 算不上 says it can't be called that at all.

还算

还算 + adjective is "fairly, reasonably": satisfied, but not delighted.

也算 adds a second label alongside another: "can count as … too".

算我的

With a meal or a cost, 算 + someone's 的 says who pays.

Where 是 goes

是 follows 算; the two don't swap.

• × 他是算我的朋友 → 他算是我的朋友

算了, "forget it", is a separate expression.