Some common synonyms for "although" are:

• even though
• though
• albeit
• despite the fact that
• in spite of the fact that
• while
• whereas
• however
• but
• notwithstanding
• nevertheless
• nonetheless

These synonyms show contrast or concession similar to "although," but may have different formalities or grammatical usage. For example, "even though," "though," and "while" are often interchangeable with "although," while "albeit" is more formal and may require structural changes in sentences. Some other alternatives like "despite the fact that" or "in spite of the fact that" are more formal and often longer expressions of contrast.

Here is a concise categorization:

Synonym| Usage Notes
---|---
even though| Strong synonym, similar use
though| Less formal, can be used at sentence end
albeit| Formal, literary, often modifies phrase
despite the fact that| Formal, introduces contrast
in spite of the fact that| Formal, similar to despite
while| Indicates contrast
whereas| Indicates contrast
however| Often at sentence start, adversative
but| Common conjunction for contrast
notwithstanding| Formal, often with noun phrases
nevertheless| Adversative conjunction or adverb
nonetheless| Similar to nevertheless

These synonyms can be selected based on the tone, formality, and sentence structure needed.