Connect two independent clauses, words, or phrases of equal grammatical rank. Use a comma before the conjunction when joining two full independent clauses.
She trained hard, but she lost.
He sings and plays guitar.
It rained, so we stayed in.
She neither laughed nor smiled.
If the dependent clause comes first, separate it with a comma. If it comes second, no comma is needed.
Because she trained daily, she won.
We'll cancel unless it stops.
Although it was late, he worked on.
She's outgoing, whereas he's shy.
Both elements must appear. The items they connect must be grammatically parallel — noun + noun, verb phrase + verb phrase, clause + clause.
Both the teacher and the students were surprised.
She not only wrote it but also performed it.
You can either call or send an email.
Neither the director nor the actors knew.
The Comma Rule — Specification Use a comma before a coordinating conjunction when it joins two complete independent clauses (She was tired, but she continued). No comma when it joins only words or phrases (bread and cheese). With subordinating conjunctions: comma when the dependent clause comes first (Because it rained, we stayed in) — no comma when it comes second (We stayed in because it rained).
Combine using a subordinating conjunction. Give both word orders.
The match was postponed because there was a storm forecast.
Clause-first → comma required. Clause-second → no comma.
Combine into one sentence using an appropriate coordinating conjunction.
Two independent clauses joined by but → comma before the conjunction.
Rewrite using not only … but also. Keep parallel structure.
Both slots take verb phrases → parallel. "In it" avoids repeating "in French."
Combine using a subordinating conjunction expressing concession.
or: Even though he had very little time to prepare, his speech was brilliant.
Although / even though / though all work. Despite / in spite of are prepositions — they require a noun phrase or gerund, not a full clause.
Rewrite using neither … nor.
Neither … nor is already negative — do not add not elsewhere. Verb agrees with the nearer subject (hot water → singular → is).
Combine using unless.
or: You will lose your place unless you submit the form.
Unless = if … not. Never write unless you don't — that reverses the meaning.
Join using an appropriate time conjunction.
After future time conjunctions (until, when, as soon as, before, after), use simple present — not future — in the subordinate clause.
Not only … but also — inserting she between but and also breaks parallel structure.
Two coordinating conjunctions cannot be used together. Yet (concessive contrast) is the correct single conjunction here.
Because is a conjunction — it introduces a full clause directly. Because of is a preposition requiring a noun phrase: Because of the delay…
Both … and always takes a plural verb — both subjects are included.
Whereas already sets up the contrast. The main clause does not need but as well.
Provided that introduces a conditional clause — takes simple present, not future.