When does "and" need a comma before it?

When it joins two complete sentences: Dad cooked dinner, and I washed the dishes. Each half stands alone. If the second part can't stand by itself (Dad cooked dinner and hummed), no comma is needed. The stand-alone test settles every case.

What are the joining words to watch for?

And, but, or, so, and yet are the ones on these worksheets; teachers often add for and nor to complete the famous FANBOYS set. Whichever conjunction appears, the comma's place never changes: right before it, never after.

4th grade commas in compound sentences

4th grade commas in compound sentences worksheets

A compound sentence joins two complete thoughts with a coordinating conjunction, and a comma marks the seam: the bell rang, but nobody moved. Fourth graders test each half: if both could stand alone, the comma goes before the joining word.

Free printable PDF worksheet, aligned to Common Core L.4.2.c.

Each print is a different sheet with its own answer key. You don't need to sign up.

The kind of sentences you'll fix

Add the missing comma to each sentence.

The goalie dove left but the ball went right.
Fixed: The goalie dove left, but the ball went right.
The food truck ran out of tacos yet the line kept growing.
My sister practiced her speech and the mirror heard it fifty times.

Every print pulls a new set of sentences at this level, so a make-up test or a second sibling gets a different mix.

What's on a 4th grade sheet

4th grade sheets draw from 60 sentences, 8 to a page. 4th and 5th grade print from the same 60 sentences. What changes is the standard (L.4.2.c here) and the teaching notes below.

A few of the sentences, as the answer key corrects them:

It rained all day, so we read inside.
Jordan sprained his ankle, but he cheered from the bench.
The rain soaked the field, but the match went on.

Fix it. Add the missing comma to each sentence. 8 sentences to fix per page.
Choose the sentence. Circle the letter of the sentence with the comma in the right place. 8 questions per page.

Every version prints on US Letter or A4, with its answer key on the last page.

How to teach this

Teach the two-thumbs test: cover each half of the sentence and ask whether it could stand alone. Two yeses mean a comma before the conjunction. A comma after the conjunction (rained so, we) reads strangely aloud, so hearing the sentence is a dependable check.

Watch for: The comma goes before the conjunction, never after it: rained, so we (not rained so, we). If the second half can't stand alone (I ran and jumped), no comma is needed.

Common questions about 4th grade commas in compound sentences

When does "and" need a comma before it?: When it joins two complete sentences: Dad cooked dinner, and I washed the dishes. Each half stands alone. If the second part can't stand by itself (Dad cooked dinner and hummed), no comma is needed. The stand-alone test settles every case.
What are the joining words to watch for?: And, but, or, so, and yet are the ones on these worksheets; teachers often add for and nor to complete the famous FANBOYS set. Whichever conjunction appears, the comma's place never changes: right before it, never after.

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Aligned to Common Core L.4.2.c. Reviewed by the One more sheet team. Content version 241, updated October 2026.

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